Verbal Ability - Idioms and Phrases - Discussion

I can't understand. Please, anyone, help me to get this.

I can't understand please anyone explain in detail.

I can't understand. Please explain in detail.

Thanks @Jose.

To be of pure heart after telling the truth or signifying the fact.

The wording in the correct answer is wrong. The preposition ' of' is unnecessary. The correct form is ' to confess without reserve'.

The word breast is close to the heart. While the clean means clear your conscience from all doubt and guilt.

The word "clean" means to make it pure, erase, wipe out so in the given option "To confess without of reserve" - the word confess means to come out with the truth and come clean of without being party to any crime or hidden incidents.

Please explain it clearly.

The Oxford English Dictionary defines the noun breast as 'the two soft protuberances situated on the thorax in females'. The meaning used in 'make a clean breast of it' is an earlier and less literal one. The 'breast' there is the seat of the one's emotions and secrets; one's 'heart'. "To make a clean breast of" means to speak openly and honestly about something that has previously been lied. Eg: The judge will give the convict a lighter sentence if he makes a clean breast of his involvement with the crime.