Exposure to Light Redistributes Auxin to the Opposite Side of the Stem

Exposure to light redistributes auxin to the opposite side of the stem or root that is exposed to light. In stems, this redistribution of auxin causes the stem to grow and bend toward the light. In contrast, roots bend away from the light as they grow. What may be an advantage of the difference in bending of roots and stems?

A) When stems bend toward the light as they grow, the leaves will shade the stem and keep it from getting too hot.
B) When roots grow away from the light, they will grow deeper into the soil where they can absorb water and nutrients.
C) When roots grow away from the light, the root cap will not be lost.
D) When roots grow away from the light, light sensitive statoliths drive the bending of the cells back to the ground.