Question

The film was funny........ the end
(choose suitable preposition)

Answer 1

your answer is

the film was funny till the end

Answer 2

The film was funny at the end.  In the following question there was a preposition missing.

A preposition is a word which connects a noun, pronoun or a noun phrase with other parts of the sentence.

Prepositions can be confusing at times. There are no particular rule or formula for using a oreposition in a sentence. Few prepositions are "on", "at" and"in".