Final answer:
The disagreements between the House and Senate versions of a tax bill are resolved by the D. Conference Committee, which reconciles the differences and sends the unified bill back to both chambers for approval.
Step-by-step explanation:
When the House and Senate versions of a tax bill are not in agreement, the disagreements are typically resolved by the D. Conference Committee. The conference committee consists of members from both the House of Representatives and the Senate and is tasked with reconciling the differences between the respective versions of legislation passed by each chamber.
Once the committee reaches an agreement, the revised bill is sent back to both the House and the Senate for a final vote. Technically, all bills for raising revenue must originate in the House of Representatives, as specified by Article I, Section 7 of the Constitution, but the Senate may propose or concur with amendments as with other bills. The conference committee plays a crucial role in the legislative process, ensuring a single unified bill is sent to the President for potential enactment into law.