With reference to "water vapour", which of the following statements is/are correct?

1. It is a gas, the amount of which decreases with altitude.

2. Its percentage is maximum at the poles.

Select the answer using the code given below:

1. (a) 1 onlyCorrect answer
2. (b) 2 only
3. (c) Both 1 and 2
4. (d) Neither 1 nor 2

Answer: (a)