A government shutdown is often the result of disagreement between
A. the president and Congress
B. the House of Representatives and the Senate
C. the federal and state governments
D. the bureaucracy and Congress
E. the government and the electric company
Either Option A or Option B could be correct. In our current situation, Option A is the better answer, but that could be different in the future.
Right now both houses of Congress are controlled by the Republican Party. Meanwhile, the president, Barack Obama, is a member of the Democratic Party. In addition, tensions are very high between the Democrats and the Republicans right now, making it very hard for any major legislation to satisfy both parties. This means that the two houses of Congress are likely to agree on major issues and President Obama is likely to disagree with them. The most likely cause of a government shutdown in the near future is a disagreement between Congress and the President over federal funding for Planned Parenthood. All of this means that Option A is the correct answer right now.
However, Option B could easily be correct as well. There are times when the House and Senate are controlled by different parties. For example, the Republicans have controlled the House since 2011. During that time, the Democrats controlled the Senate until the 2015. When there is a division like this, it is easily possible for conflict between the House and the Senate to cause a shutdown. Presumably, the President would side with whichever house was controlled by his or her party.
Thus, Option B is a possibility, but Option A is the correct answer right now.