D). If the crosswalks were painted it would it make it more visible to cars. It would also be more visible to pedestrians so they don't Jay walk and get hit.
I think that C. 30 is the minimum recommended spf for sunblock.
3) because during the menstrual cycle the body is already trying to clean out the uterine lining and the old egg is already in that. So having a new egg drop in form the ovary at the end of the cycle makes more sense.