Choose the best response to the question.
¿qué abres tú?
a. yo abres la puerta.
b. yo abro la puerta.
c. yo abre la puerta.
d. yo abrimos la puerta.
p. s. i have an idea what the answer is, but i need better explanation so i can understand it better? : )

The answer is B.
The question is "What you open" or "what are you opening"
And she answer "Yo abro la puerta" means "I open the door"
"Abres" means when you're talking to someone else like "you open the door"
"Abre" is like telling someone "Open the door!" 
"Abrimos" refers to more than one people "We open the door"
I hope you got it. 
I'm not the best explaining things but hope this helps you.
Spanish Native.

True if this is a true or false questionshoped this : )