下列各句中，画线成语使用恰当的一项是

I suggest you delete the useless files on the computer which _______ too much space

The US President Obama told the students that he ______ by a single mother who were strict with him and wished him great success in his studies

I hear you have________that new motor for two months already． —I didn’t buy it．The price is a bit_________，I think．

______ is your father —He’s a driver.