Complete the series: B, D, F, H, ?

D. I

What comes next in the series: A, E, I, M, ?

A. O

Find the odd one out in the series: A, D, G, J, M, P, ?

B. R

B, D, F, H, ?

A. J

Find the odd one out in the series: A, C, E, G, I, K, M, O

D. O