The correct answer is B. to.
The preposition “to” is used to indicate the person or thing that is the recipient of an action. In this case, the action is “shouting” and the recipient is “his mother”.
The other options are incorrect because they do not make sense in the context of the sentence. The preposition “on” is used to indicate a location or position on a surface. The preposition “at” is used to indicate a location or position in space. The preposition “in” is used to indicate a location or position inside something.
Here are some examples of how the preposition “to” is used in other sentences:
- I gave the book to my friend.
- I wrote a letter to my mother.
- I talked to my teacher about my homework.
- I went to the store to buy some milk.
- I came to the party late.