Identify the missing letter in the series: Z, Y, X, W, ?

A. V

What letter comes next in the series: A, C, E, G, ?

A. I

Identify the missing letter in the series: Z, X, V, T, ?

C. Q

Z, X, V, T, ?

D. U

What is the next letter in the series: A, C, E, G, ?

B. H