You have been growing some animal cells in culture. the cells grow well for several weeks and then their growth slows down. you conduct some tests and determine that there is a lot of lactic acid in the culture fluid. which of the following is the most likely explanation for the poor growth of the cells?

a) there is too much glucose in the culture fluid.
b) there is not enough glucose in the culture fluid.
c) there is too much oxygen in the culture fluid.
d) there is not enough oxygen in the culture fluid.