The answer is D. For A to work it would have to be "Am I going with you to the grocery store? For B to work it would have to be "You children have to wash your hands after playing outside." For C to work it would have to be "Don't you want to know whats inside the box?" Generally the best way to solve these problems is through process of elimination, just so that you're sure that your answer is correct.
I believe it would be A because they have used evidence and clarity on the topic as-well as keeping it formal.
The correct answer should be
B) Through his actions
