My question is how do i solve #5? also can someone explain what f1 & f2 generations are?

The table below shows data for a population of fish in a pond. fish body color # of fins scales? tail shape a silver 4 yes fan b pink 4 yes flat c black 4 yes fan d orange 4 yes flat e orange 4 yes fan f silver 4 yes flat which of the above characteristics would be most in developing a classification system for the fish? a. body color and tail shape b. presence of scales and tail shape c. body color and number of fins d. number of fins and presence of scales