If a toxin disrupted the Na+/K+ pump so that intracellular sodium rose substantially while intracellular potassium fell, which immediate cellular effect would you predict?

Water would immediately leave cells, causing cell shrinkage, because the pump failure increases intracellular negative charge and repels water molecules out of the membrane.

A long-term increase in extracellular potassium concentration would occur instantaneously, producing immediate vasoconstriction in surrounding capillaries.

Water would flow into cells by osmosis and cells would swell because intracellular osmolarity increased from the extra sodium present.

Cells would maintain normal volume because the leak channels would compensate fully for pump failure and keep gradients unchanged for several hours.