A man is standing on a sensitive balance. If he inhales deeply, the reading of the balance

The correct answer is (a).

When a man inhales deeply, his lungs fill with air. This increases the mass of his body, which in turn increases the reading on the balance.

Option (b) is incorrect because the man’s weight does not decrease when he inhales deeply. In fact, his weight may actually increase slightly due to the increased mass of his lungs.

Option (c) is incorrect because the reading on the balance will change when the man inhales deeply.

Option (d) is incorrect because the reading on the balance will increase when the man inhales deeply, regardless of the atmospheric pressure.