Please help! Help would be amazing!!! 2 questions!

1. Deepwater currents are driven by which of the following?
A. temperature only
B. salinity only
C. temperature and salinity
D. temperature and pressure

2. Upwelling is the upward replacement of ________, nutrient-poor, surface water by ________, nutrient-rich, deep water.
A. cooler, warmer
B. warmer, cooler
C. saltier, warmer
D. cooler, saltier