Explanation:

Let’s break this down one step at a time:

- The question asks: How many symbols are there in the series which are immediately preceded and followed by a letter?

- Let's go through the series step by step:

M L O $ Q 2 Z ? < X F U ! @ V 7 3 5 A Y 6 8 * B > H 9 % S V U + 1

- Scan for symbols ($ ? < ! @ * > % +) that fit the requirement: a symbol sandwiched by letters.

1. $: O $ Q — O and Q are both letters. So $ counts.

2. ?: Z ? < — Z is a letter, but < is a symbol, so not counted.

3. !: U ! @ — U is a letter, @ is a symbol, skip.

4. @: ! @ V — ! is a symbol, V is a letter, skip.

5. \*: 8 * B — 8 is a digit, so doesn’t count.

6. >: B > H — B and H are both letters. Yes, counts.

7. %: 9 % S — 9 is a digit, so skip.

8. +: U + 1 — U is a letter, 1 is a digit, skip.

- So when we add it up, only $ and > fit the bill. That’s exactly two symbols.

- Checking your options:

- Option 1: 1

- Option 2: 2   

- Option 3: 3

- Option 4: more than 3

- Option 5: None

Option 2 is correct.