C. sexual reproduction
d. asexual reproduction

6.how are phytoplankton important for whales?
a. they are eaten by some whales
b. they provide calcium carbonate for whales
c. they provide the whales with shelter
d. they recycle wastes into materials whales can eat

7. which of the following events might lead to an algal bloom
a. nitrogen-rich fertilizer washes off of fields into the ocean
b. oxygen is removed from the ocean by decomposition
c. new sewage plants remove more wastes from discharge
d. the population of baleen whales increases

i need because my grades arent very good