The primary function of the kidney is to exchange molecules across a membrane between the blood and the urine. One type of kidney cell has a basic rectangular shape, except for a single surface, which is lined with tiny, finger-like projections that extend into the surrounding extracellular space. Which of the following best explains the advantage these projections provide the cell? The projections increase the volume of the cell without affecting the surface area, which increases the metabolic needs of the cell. B The projections increase the surface area-to-volume ratio of the cell, which allows for more efficient nutrient exchange with the environment. The projections increase the speed at which an individual molecule can move, resulting in faster nutrient Which of the following best explains the advantage these projections provide the cell? A The projections increase the volume of the cell without affecting the surface area, which increases the metabolic needs of the cell. B The projections increase the surface area-to-volume ratio of the cell, which allows for more efficient nutrient exchange with the environment. The projections increase the speed at which an individual molecule can move, resulting in faster nutrient exchange with the environment D The projections increase the selectivity of the membrane because the small size of the projections limits the number of transport proteins that can be embedded in the membrane.