1. Asphyxiation is a hazard posed by Compressed Natural Gas (CNG) vehicles and can be detected when you notice

this smell.

Smell of Mercaptan will allow us to  detect the Compressed natural gas. The smell is similar to the LPG used in our homes for cooking.

Explanation:

Compressed natural gas is heavier than air and tends to settle down near the ground. In case there is a leakage of CNG  the air near the ground surface will be displaced and get filled with CNG. This may result in aphyxiation i.e. lack of oxygen in enclosed places.

CNG is odorless and cannot be detected by smell. In order to make the detection possible, a small amount of mercaptan is added to CNG so that its smell is easily detected.

answer:

explain:

we don't have any choices.