At what points during the year are fish—which need a large amount of dissolved oxygen—most likely to be evenly distributed throughout the water of a lake that freezes over in winter? (4 points)

Select one:
a. Spring and fall when warm and cold water mixes
b. Fall and winter when the water is warmer
c. Summer and winter when warm water settles on the bottom
d. Spring and summer when the cold water settles on top