Question

muscular strength and endurance is the ability of the cardiovascular and respiratory systems to efficiently transfer oxygen and nutrients to the skeletal muscles, true or false?

Answer 1

This isn't completely true. Muscular strength is determined by the maximum force which a completely contracted muscle can produce. So this hasn't that much to do with the ability of transfering oxygen and nutrients to the skeletal muscles. On the other hand, it is true that endurance is dependent on the ability to efficiently transfer oxygen and nutrients. 

Answer 2

It would most likely be true, unless they gave you in the explanation it was the circulatory system.