We have, in the sequence after STEP III:
÷ $ + H A 9 # K L N 3 B 8 5 4 1 % X 2 > T O G J V Y @ &
Here, the symbols which are followed by letter and preceded by a number are #, % and >.
Hence, the correct answer is option 3.
Final Solution:

Given Sequence:

H 8 J + A 9 # K Y @ L 4 $ N 5 3 B G & % X 1 ÷ 2 V > T O

Sequence after STEP I:

H 8 + A 9 # K @ L 4 $ N 5 3 B & % X 1 ÷ 2 > T O G J V Y

Sequence after STEP II:

H + A 9 # K @ L $ N 3 B & 8 5 4 1 % X ÷ 2 > T O G J V Y

Sequence after STEP III:

÷ $ + H A 9 # K L N 3 B 8 5 4 1 % X 2 > T O G J V Y @ &

Common Explanation:

We have the given alphanumeric sequence,

H 8 J + A 9 # K Y @ L 4 $ N 5 3 B G & % X 1 ÷ 2 V > T O

Here, we also have a hint that while solving the alphanumeric sequence STEP II is applied after STEP I and STEP III is applied after STEP II.

So, in the above alphanumeric sequence firstly we will apply Step I then Step II and at last Step III will be applied.

Now, in the STEP I – The letters which are followed by a symbol are to be arranged in alphabetical order at the right end of the series. (Just after O)

Here, the letters which are followed by a symbol are ‘J’, ‘Y’, ‘G’ and ‘V’.

H 8 J + A 9 # K Y @ L 4 $ N 5 3 B G & % X 1 ÷ 2 V > T O

Now, these letters will be arranged in alphabetical order at the left end of the series.

It is also given that the new arrangement will start just after O.

After applying the above conditions the given alphanumeric sequence can be written as:

H 8 + A 9 # K @ L 4 $ N 5 3 B & % X 1 ÷ 2 > T O G J V Y

Thus, the alphanumeric sequence obtained after applying Step I is:

H 8 + A 9 # K @ L 4 $ N 5 3 B & % X 1 ÷ 2 > T O G J V Y

In the above alphanumeric sequence Step II will be applied.

In the STEP II – The numbers which are preceded by a consonant will be arranged between ‘&’ and ‘%’ in descending order.

In the alphanumeric sequence that obtained after Step I, the numbers which are preceded by a consonant are ‘8’, ‘4’, ‘5’ and ‘1’.

H 8 + A 9 # K @ L 4 $ N 5 3 B & % X 1 ÷ 2 > T O G J V Y

It is also given that the numbers which follows the given criteria will be arranged between ‘&’ and ‘%’ in descending order.

After applying the above conditions STEP II of the given alphanumeric sequence can be written as:

H + A 9 # K @ L $ N 3 B & 8 5 4 1 % X ÷ 2 > T O G J V Y

Thus, the alphanumeric sequence obtained after applying Step II is:

H + A 9 # K @ L $ N 3 B & 8 5 4 1 % X ÷ 2 > T O G J V Y

Now, in the above alphanumeric sequence Step III will be applied.

We have, in the STEP III – The symbols which are preceded by a letter will be arranged such that 1st symbol will be arranged at the left end, the 2nd symbol will be arranged at the right end, 3rd symbol will again be arranged at the left end and so on.

In the alphanumeric sequence that obtained after Step II the symbols which are symbols which are preceded by a letter are +, @, $, & and ÷.

H + A 9 # K @ L $ N 3 B & 8 5 4 1 % X ÷ 2 > T O G J V Y

It is also given that these symbols will be arranged such that 1st symbol will be arranged at the left end, the 2nd symbol will be arranged at the right end, 3rd symbol will again be arranged at the left end and so on.

After applying the above conditions the given alphanumeric sequence can be written as:

÷ $ + H A 9 # K L N 3 B 8 5 4 1 % X 2 > T O G J V Y @ &

Thus, the alphanumeric sequence obtained after applying Step III is:

÷ $ + H A 9 # K L N 3 B 8 5 4 1 % X 2 > T O G J V Y @ &