Final answer:
C. Shrink. The 3% saline solution given to a patient with diarrhea will cause the cells to shrink.
Step-by-step explanation:
The 3% saline solution given to a patient with diarrhea will have the effect of causing the cells to shrink. This is because the solution is hypertonic, meaning it has a higher concentration of solutes compared to the cells. In a hypertonic solution, water will leave the cells, leading to cell shrinkage.