Answer : The correct option is, (a) true
Explanation :
Ozone layer : It is a layer which is present in the stratosphere region. Ozone layer is the layer which absorbs more amount of the ultraviolet rays which is the more harmful rays for us. That means ozone layer protect us from the harmful rays (UV rays). Ultraviolet rays causes the skin cancer. When the ultraviolet rays reaches directly to the earth, it cause many type of diseases.
When the hole in the ozone layer then it can lead to increases in skin cancer.
Hence, the given statement is true.