An experimental set-up is given here to demonstrate that `CO_(2)` is given out during respiration. Four students made the following observations marked as I, II, III and IV.
I. Level of water remained the same in both the beaker and the delivery tube
II. Level of water increased in the delivery tube
III. Level of water reduced in both the beaker and the delivery tube
IV. Water ascends into the delivery tube and back flows into the beaker.
Which one of the above is the correct observation?

Options

A. I
B. II
C. III
D. IV

Answer

B