If there are two goods and if income doubles and the price of good 1 doubles while the price of good 2 stays constant, a consumer's demand for good...

1.    If there are two goods and if income doubles and the price of good 1 doubles while the price of good 2 stays constant, a consumer's demand for good

a.    1 will increase only if it is a Giffen good for her.

b.    2 will decrease only if it is a Giffen good for her.

c.    2 will increase only if it is an inferior good for her.

d.    2 will decrease only if it is an inferior good for her.

e.    None of the above.

Can you please tell me the answer and how you got it?