Which of the phrases given in the options should replace the word/phrase that is underlined in the sentence to make it grammatically correct? if the sentence is correct as it is given and no correction is required, select 'No correction required' as the answer.
To be successful, you must understand why your failure in the past and take steps to prevent it from happening again.
1
why had you failed
2
because you have failed
3
why you had failed
4
that your failure
5
No correction required