Which of the following statements best would best explain the inability of an animal cell to reduce the Ca2+ concentration in its cytosol?

A) The calcium-gated ion channels in the cell membrane are inactive.
B) Excessive amounts of calcium are transported from the cytosol into the endoplasmic reticulum.
C) Insufficient amounts of ATP are present in the cytosol.
D) Insufficient numbers of protein kinases are present in the cell.