Final answer:
A cell must routinely divide through mitosis to maintain a balanced surface area-to-volume ratio, which is crucial for efficient nutrient and waste exchange. The correct option is d. Increase surface area while keeping the volume constant.
Step-by-step explanation:
In order to maintain a balanced ratio between surface area and volume and effectively reduce its size, a cell must routinely divide through mitosis. This is because as a cell grows, its volume increases more rapidly than its surface area, leading to a decreased surface area-to-volume ratio, which can inhibit the cell's ability to diffuse substances efficiently across its membrane. Division through mitosis creates two smaller cells from one larger cell, restoring a more favorable surface area-to-volume ratio and allowing for more efficient exchange of nutrients and wastes.
Methods like excreting waste products or increasing the volume while keeping the surface area constant do not solve the issue of the disproportion between a cell’s surface area and volume. On the contrary, increasing surface area while keeping volume constant can indeed help, but this isn’t usually a routine action for reducing cell size; it's more a characteristic of specialized cells that have adapted to their functions.