The correct answer is option 2, Thioethanol. Thioethanol is a strong smelling agent that is added to LPG cylinders to help in the detection of gas leakage. LPG (liquefied petroleum gas) is a highly flammable gas and it can be dangerous if there is a leakage. To ensure safety, a strong smelling agent is added to LPG cylinders so that it can be easily detected if there is a gas leak.
Option 1, Ethanol, is not the correct answer because while ethanol does have a distinct odor, it is not used as an additive in LPG cylinders for detection of gas leakage.
Option 3, Methane, is also not the correct answer because methane is the main component of LPG and does not have a strong smell. Therefore, it is not used as a smelling agent.
Option 4, Chloroform, is not the correct answer either because it is not used as an additive in LPG cylinders and does not have a strong smell.
It is important to note that the strong smelling agent helps in the detection of gas leakage by making it easier for individuals to notice the gas leak and take appropriate measures to prevent any accidents or hazards.