Answer:
Option A, Mobile source
Step-by-step explanation:
A mobile source of pollution pollutes the environment while moving. It does not stay at one constant position like a chimney of industry or a stationary machine releasing pollutant gases. Hence, all the moving vehicles, automobiles, diesel engines etc. which release harmful things thereby degrading environment are called mobile source of pollution. Thus, a car releasing pollution while driving through the Grand Canyon will be considered as mobile source of pollution.