While conducting experiments to study the effect of various stimuli on the plants, it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bend away from a third stimulus C. The stem of the plant X, however, bends away from stimuli A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to too much weight of the earth. Keeping these points in mind, answer the following questions :(a) What could stimulus A be?(b) Name the stimulus B.(c) What could stimulus C be?(d) The branches of a fallen tree in a forest grow straight up in response to two stimuli. What could be these two stimuli out of A, B and C? Also name these two stimuli.

(a) The stimulus A could be water, as roots show the positive hydrotropism.

(b) The stimulus B could be gravity, as roots show the positive geotropism.

(c) The stimulus C could be light, as roots show the negative phototropism.

(d) The two stimuli responsible for the straight growth of the branches of a fallen tree could be B (gravity) and C (light).