If the senate changes (amends) a house bill, it must visit this committee before going to the white house.
a.)conference committee
b.)select committee
c.)special committee
d.)closed committee

The answer is "Conference Committee" where the differences are negotiated and resolved, then a vote is scheduled for the resolved bill for both the House and Senate. This time when each chamber votes, the bill upon which they vote must be IDENTICAL. If you'd like to have an example of this process, go back on C-SPAN1 and C-SPAN2 from 2009 up to Christmas time, when the Patient Protection and Affordable Care Act of 2009 (our new health care and insurance reforms law) was finally completed through maneuverings that got around the GOP's attempts to block and then sent to President Obama for his signature.