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.

Answer

(a) Water (b) Gravity (c) Light (d) B and C; Gravity and Light (or Sunlight)