An organism described as "heliotropic" has a tendancy to move towards which of these things?

The story behind the answer

Heliotropic organisms orient or move toward light—especially sunlight. The term comes from Greek: “helios” (sun) + “tropos” (turn). Many plants exhibit heliotropism to maximize photosynthesis; classic examples include young sunflower buds and certain leaves that track the sun across the sky.

How it works: the plant hormone auxin redistributes to the shaded side of a stem, causing those cells to elongate more and bend the plant toward the light. Fun fact: mature sunflower heads usually settle facing east rather than continuing to track the sun. Memory tip: think “Helios,” the sun god—heliotropism is