PRESENT CONTINUOUS FOR FUTURE ARRANGMENTS

GRAMMAR CHALLENGE
“_____ the computer tonight? I want to check my email when I get home.”
a) Are you using
b) Do you use
c) You are using

 
 The correct answer is (a): “ARE YOU USING the computer tonight? I want to check my email when I get home.”
This is a question about a future arrangement, but using the present continuous tense.

For more on the present continuous for future arrangements: http://bbc.in/1nAhCjZ