Explanation:

To find the correct synonym for the given word we will first understand the meaning of the word CLIMAX and then the meaning of the words given in the options.

CLIMAX - the most intense, exciting, or important point of something

Now meaning of the words in option.

Culminate - reach a climax or point of highest development.

Preface - reach a climax or point of highest development.

Prologue -  an event or act that leads to another.

Epilogue - a section or speech at the end of a book or play that serves as a comment on or a conclusion to what has happened.

Option 1 is the correct answer as it is the most suitable synonym for the given word CLIMAX.