His father ordered him to go to his room and study.
A. His father said, "Go to your room and study."
B. His father said to him, "Go and study in your room."
C. His father shouted, "Go right now to your study room"
D. His father said firmly, "Go and study in your room."
Answer: Option A

Answer should be B. His father said to him, "Go and study in your room
When we will convert into direct speech the command will remain the same ,only 'his' will get replaced by 'your' hence option A is the most appropriate one