Answer: Letter B
Step-by-step explanation:
The question requires us to choose, among the options given, which one presents a reason for an experiment being performed in a well ventilated area.
To answer this question, let's analyze the options given and the characteristics of the gases considered in these options (oxygen, hydrogen and helium gas):
- Helium gas is an inert gas, as it is formed by atoms of a noble gas (known for being inert);
- Although oxygen gas might cause other materials that burn to ignite more easily and burn more rapidly, it is not a flammable gas itself;
- On the other hand, hydrogen gas is very flammable and it must be handled carefully.
Considering the information above, we can make the following remarks about the options given:
- Letter a is not correct because oxygen gas is not flammable;
- Letter b is not correct because hydrogen gas is not inert;
- Letter c is correct: hydrogen gas is very flammable and it might offer a risk to the lab users;
- Letter d is not correct because helium gas is actually inert, and not flammable.
Therefore, the best option to answer this question is letter B.