The answer is A. Walking is the ideal work out before a run because it gets your body from sitting mode into workout mode in the least intense way. The motion of walking takes the muscles, tendons, and joints through a range of motion similar to what it will go through in running.
Tad poles have gills that help them breathe underwater. frogs have lungs that help them breathe underwater. tadpoles have tails and fins to help them swim underwater. frogs have arms and legs to help them swim.