Between 2011 and 2017, which groups were involved in the conflict in Yemen?

A.
the Assad government, Arab Spring protesters, and Saudi-led forces

B.
pro-democratic forces, the Gulf Cooperation Council (GCC), the Hadi government, Houthis, and ISIS

C.
Hamas, the PLO, Shia Arabs, Sunni Arabs, and the Saleh government

D.
the Baath Party, the Kurds, southern rebels, and the Yemeni army