Help verbs (auxiliary verbs)

[ronny]

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #120 "Perfect Tenses", question 10

No-one ......... believe your story when you tell them.

(a) will
(b) did
(c) has
(d) is

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #120 "Perfect Tenses", answer 10

No-one will believe your story when you tell them.

Correct answer: (a) will
_________________________

Why not use will ?

[Mister Micawber]

Yes, will is correct.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mister Micawber