Explanation:

Let's break down the sequence:

- 28, 18, 12, 8, ?

Let's look for a pattern:

- 28 - 18 = 10

- 18 - 12 = 6

- 12 - 8 = 4

The differences are 10, 6, and 4. Notice that the difference is reducing each time by 4, then 2:

- 10 (reduce by 4) ? 6 (reduce by 2) ? 4

- Next difference should be 2 (since the pattern reduces by 2 each time: -4, -2, -2).

So next number: 8 - 2 = 6

Now, check the options:

- 1) 3

- 2) 5

- 3) 2

- 4) 4

None of the options is 6. Let's check if another pattern fits.

Maybe the sequence is halving or a division pattern?

- 28 / 2 = 14 (not matching series)

Let's reconsider.

Try subtracting decreasing even numbers:

- 28 - 10 = 18

- 18 - 6 = 12

- 12 - 4 = 8

- 8 - 2 = 6

None of the options fit directly. Let's check other possible relationships.

Alternatively, let’s check if there's a multiplication ratio:

- 28 / 18 ˜ 1.56

- 18 / 12 = 1.5

- 12 / 8 = 1.5

The ratios do not seem consistent.

Maybe try further, but based on above, perhaps there’s an error in the options.

But with pure subtraction:

- 28 - 10 = 18

- 18 - 6 = 12

- 12 - 4 = 8

- 8 - 2 = 6

Expected next is 6, but not in options, so let's double-check differences:

- If pattern is subtracting consecutive even numbers: 10, 6, 4, 2

But in your options, none matches. If we overlook the pattern, perhaps 4 is possible if subtracting by 4 each time after 12.

But sequence shows:

- 28, ? -10 ? 18, ? -6 ? 12, ? -4 ? 8, ? -2 ? 6

But since 6 isn't available, maybe option 4: 4 is closest under a possible typo or misprint.

Summary of options:

- 1. 3: Not fitting any pattern above

- 2. 5: Not explained by the established pattern

- 3. 2: Would require a -6 difference, not matching

- 4. 4: Would require a -4 difference, which already occurred previously

Even so, strictly by the pattern, none fit exactly. The only plausible answer by continuity and reduction is option 4: 4 if sequence error.

Correct Answer: Option 4 – 4