In the context of the control of cell size, what most directly limits the maximum size of a cell as it grows larger?

• A. A decreasing surface area-to-volume ratio that constrains nutrient uptake and waste removal across the plasma membrane
• B. An increasing surface area-to-volume ratio that causes excessive loss of cytosolic proteins through the membrane
• C. A fixed number of chromosomes that prevents additional gene transcription once the cell reaches a threshold volume
• D. The inability of mitochondria to replicate, which stops ATP production entirely beyond a critical cell diameter

Answer: (A)