请教一道Must Be True 题， 已然乱了……

Light is registered in the retina when photons hit molecules of the pigment rhodopsin and change the molecules' shape. Even when they have not been struck by photons of light, rhodopsin molecules sometimes change shape because of normal molecular motion, thereby introducing error into the visual system. The amount of this molecular motion is directly pproportional to the temperature of the retina.

which one of the following conclusions is most strongly supported by the information above?

(A) The temperature of an animal's retina depends on the amount of light the retina is absorbing.
(B) The visual systems of animals whose body temperature matches that of their surroundings are more error-prone in hot surroundings than in cold ones.
(C) As the temperature of the retina rises, rhodopsin molecules react more slowly to being struck by photons.
(D)Rhodopsin molecules are more sensitive to photons in animals whose retinas have larege surface areas than in animals whose retinas have small surface areas.

但是题中也没用说温度越高或越低motion会怎样啊

Must be true question is the easiest of all.

In this case, a list of facts are provided and you are asked to find one answer choice which is supported by those facts.

What you need to do is to understand all the facts.
1) When light hits the molecule R, R changes its shape.
2) When R changes its shape, light is registered in retina (meaning the eye sees light).
3) Normal molecular motion of R also changes R's shape (thus causes error for the eye to recognize light since light does not hit molecule R).
4) The higher the temperature, the more molecular motion.

B) is right since it could be decuced from the combination of facts 3) and 4), together with the trigger in B).