Answer:
The cell is basically like a city because there are different parts of the cell that work together to keep a system running, therefore incredibly similar to a cell. There are parts to the cell such as the vacuole which acts as the storage for a cell, like the storeroom or bank in the city, and the lysosome which cleans up and recycles for the cell in away, acting as the recycle center or such for a city. Just like these few cell parts, there are many other parts which each have their respective "role" to functioning as a "city", and for those reasons a cell is like a city.
C. Reproductive because the circulatory assists the runner in pumping blood into his body, his muscular is the muscles the runner uses to run, and the skeletal supports the muscles and the rest of the body while he is running. The reproductive system isn't actively being used during this time
Decrease mass keep volume
The endocrine system releases hormones into the bloodstream, most of which are released by the pituitary gland
i believe that to be correct