How Do Viability Stains Usually Distinguish Between Living Cells and Dead

Multiple Choice

How do viability stains usually distinguish between living cells and dead cells?

A) The chemical fluoresces only when bound to ribosomes that are actively synthesizing proteins.
B) The chemical stain is taken up by living cells and once metabolized becomes fluorescent.
C) The dye specifically targets intact cytoplasmic membranes.
D) The dyeʹs fluorescence is quenched by dead cells.