Refer to the Figure Below, Illustrating Early Studies of Phototropism

Refer to the figure below, illustrating early studies of phototropism. After blindfolding different parts of the seedling and watching the response to a light stimulus, the Darwins concluded that

A) seedlings in natural conditions do not respond to the direction of a light stimulus.
B) the hormone auxin detects the direction of a light stimulus.
C) the part of the plant that detects the direction of a light stimulus is located at the base of the shoot.
D) the part of the plant that detects the direction of a light stimulus is located in the roots.
E) the part of the plant that detects the direction of a light stimulus is located in the shoot tip.