To find the missing letter in the given sequence A-C-E-G-I-K-M-O-Q-?, let's analyze the pattern:
The sequence consists of alternating letters from the alphabet and the letter "Q". The alphabetic letters are increasing in a consecutive manner, with a step of 2 between each letter.
Starting with the letter "A", the pattern is as follows:
A (+2) C (+2) E (+2) G (+2) I (+2) K (+2) M (+2) O (+2) Q
To continue the pattern and find the missing letter, we need to add 2 to the last letter "Q":
Q (+2) = S
Therefore, the missing letter in the sequence A-C-E-G-I-K-M-O-Q-? is S.
The correct answer is E) S.