A verb is used to express an occurrence, action, or state. It is the grammatical centre of the predicate in a sentence.
Option 'A' is correct for the given sentence as it talks about the future, the word 'fail' indicates the use of expressing necessity in the future.
Option'B' is incorrect as 'did' is used in the past tense.
Option 'C' is incorrect as does is a singular verb and it is used with third person singular number(He, She, It) but the subject in the given sentence is the first person ('I"). Hence this option is incorrect for the given sentence.
Option 'D' is incorrect as the second part of the option 'won't have' does not fit in the given sentence.