The right answer is True.
Chemically speaking, there is only one molecule of ozone. It is formed of three oxygen atoms (O3). Yet ozone is a gas that can be as useful as it is particularly dangerous.
It is in the stratosphere, at an altitude of between 10 and 40 kilometers, that we find the good ozone, the so-called stratospheric ozone. Here, it is used to absorb the ultraviolet radiation that comes to us from the Sun. Radiation particularly dangerous for living beings, causing most skin cancers.
It is in the lower atmosphere, the one we breathe every day, that bad ozone is found. This gas becomes dangerous when volatile organic compounds or oxides of nitrogen, essentially coming from motor vehicle exhausts, release, under the effect of sunlight, an oxygen atom which can then be used to form ozone.
The harmful effects of ozone on living beings are numerous: tingling of the eyes, coughing, difficulty in breathing, migraines, weakening of the immune system, etc.