Choose the missing terms out of the given alternatives : Z, W, S, P, L, I, E ?

B
D
F
K

The missing term is T. The sequence is a simple alternating repetition of the letters Z, W, S, P, L, I, E, T.

The first letter is Z. The second letter is W, which is one letter after Z in the alphabet. The third letter is S, which is two letters after W in the alphabet. The fourth letter is P, which is three letters after S in the alphabet. The fifth letter is L, which is four letters after P in the alphabet. The sixth letter is I, which is five letters after L in the alphabet. The seventh letter is E, which is six letters after I in the alphabet. The eighth letter is T, which is seven letters after E in the alphabet.

Therefore, the missing term is T.