A group of 100 female water fleas was placed in each of three culture jars of different sizes. The graph below shows the average number of offspring produced per female each day in each jar. A) water fleas have fewer offspring when they are thinly populated.

B) the ability of a water flea to produce offspring is affected by population density.

C) the reproduction rate of water fleas increases steadily after 20 days.

D) water fleas produce more offspring when they are crowded together.