Answer to Question 1
The low-pressure belt at the equator is due to more direct or incident solar radiation during most of the year. This causes both the land and ocean to heat up, as well as the air above the land and ocean. Warmer temperatures cause more evaporation, especially over the ocean, creating relatively light air that is both warm and humid. This warm, moist air tends to rise vertically, creating low air pressure. In contrast, air at the poles is relatively dry and very cold, which causes the air to descend back towards the surface, creating high air pressure.
Answer to Question 2
A