If 1 is added to each odd digit and 2 is subtracted from each even digit in the number 7318546, which of the following digits will be second from the left?

Given: 7318546

Add 1 to each odd digit and subtract 2 from each even digit.

7 → odd → 7 + 1 = 8

3 → odd → 3 + 1 = 4

1 → odd → 1 + 1 = 2

8 → even → 8 − 2 = 6

5 → odd → 5 + 1 = 6

4 → even → 4 − 2 = 2

6 → even → 6 − 2 = 4

New number: 8426624

Now, the second digit from the left is: 4

So, 4 digits will be second from the left.

Thus, correct option is (a).