Question

Which of the following sentence is it the mai which of the following sentence is a command?

Answer 1

The answer is B. it is a command since it is telling someone to do something

Answer 2

B is a command , when giving a command you are asking or telling to" in this case she/he is asking , "Please lock the door when you leave."
 
also because you are telling someone to do something. 

i hope this helps