Even in the absence of sperm, metabolic activity in an egg can be ...

[sammy]

Even in the absence of sperm, metabolic activity in an egg can be artificially activated by
A) abnormally high levels of carbonic acid in the cytosol.
B) abnormally low levels of extracellular oxygen.
C) injection of calcium ions into the cytosol.
D) exposure to the low pH of the uterus.
E) depletion of its ATP supplies.

[Yolanda]

For sure it has to be C Mark as solved once you're done!