Which of the Following Is the Best Explanation for the Inability

Multiple Choice

Which of the following is the best explanation for the inability of a specific animal cell to reduce the Ca2⁺ concentration in its cytosol compared with the extracellular fluid?

A) blockage of the synaptic signal
B) loss of transcription factors
C) insufficient ATP levels in the cytoplasm
D) low oxygen concentration around the cell
E) low levels of protein kinase in the cell