Please help with right answers, not “b or c”. and things like that

Which statement is a reason to support population regulation? a) it is unethical for us to control birth control rates b) humans have the freedom to produce as many children as desired c) the gap between the rich and poor has been narrowing since 1960 d) billions more people on the earth will intensify many environmental and social problems

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.