In what type of plea bargain does the defendant plead guilty to a less serious offense than the one charged?

The answer is  charge bargaining
This type of bargain is usually being made if a defendant posess a certain information that wanted by the prosecutor, so they made a deal that beneficial for both of them.
For example, a drug seller that exchange the reduction of his sentence with information regarding his drug supplier.

This question is an opinionated one, and we don’t know anything about the module or anything, thus we can not answer it. but if you are having trouble on what it is asking basically it is just asking to (using your knowledge on the topic) say which topics you were most interested and which were the most challenging.hope this : p