What is the 10th letter in the English alphabet?

A. J

If the 15th letter of the alphabet is replaced by 'X', what is the new letter at the 15th position?

B. X

In the series A, B, C, D, E, F, G, how many times does the letter 'C' appear?

A. 1

In the sequence A, B, C, D, E, F, G, what is the 3rd letter?

A. C

What is the 15th letter of the English alphabet?

A. O