You should be ashamed . . . . . . . . your misconduct. A. to B. by C. at D. of

The correct answer is: of.

The preposition “of” is used to express possession, origin, or a part of something. In this case, the speaker is saying that the listener should be ashamed of their misconduct. This means that the listener should feel embarrassed or regretful about their actions.

The other options are not as appropriate in this context. The preposition “to” is used to express motion towards a place or person. The preposition “by” is used to express a cause or agent of an action. The preposition “at” is used to express a location or position.

Here are some examples of how the preposition “of” can be used in other contexts:

• I am proud of my children.
• The book is made of paper.
• The city is full of people.
• The teacher is in charge of the class.