Select the alphanumeric-cluster that can replace the question mark (?) in the following series.
5A, 7C, 6E, 8G, ?, 9K, 8M

Correct option is D

The series of numbers is: 5, 7, 6, 8, ?, 9, 8
Observing the sequence:
5 → 7 (increase by 2)
7 → 6 (decrease by 1)
6 → 8 (increase by 2)
8 → ? (decrease by 1)
Following this pattern, the next number should be 7.
The series of letters is: A, C, E, G, ?, K, M
Each letter progresses by skipping one letter in the alphabet:
A → C (skip B)
C → E (skip D)
E → G (skip F)
G → ? (skip H)
Following this pattern, the next letter should be I.
The alphanumeric cluster that should replace the question mark is 7I.
Correct Answer (d) 7I.