What type of fracture does not protrude the skin?

answer; i believe that the correct answer is (b) is a factor associated with physical activity and heart disease;

during longer space exploration trips, crewmembers may develop vision impairment risks and short-term cardiac atrophy or a decrease in the size, strength, weight, and activity of the heart during space flight because they can experience microgravity. in addition, the long-term medical condition is loss of bone mineral density and radiation exposure.