The best answer is option D.
Acid rain is simply rainfall that has been rendered acidic due to water vapor reacting with nitrogen oxide ad sulphur dioxide very high up in the atmosphere.
Acid rain is not only a threat to the ecosystem and environment, but also seriously damages buildings and sculptures.
Marble and limestone are especially vulnerable to acid rain. This is because the two building or construction materials contain calcite which is easily dissolved by acid.
Concrete surfaces and paint finishes are also seriously damaged by acid rain.
Velocity is a vector quantity which means it has both magnitude and direction means in order to calculate it another vector quantity is used which is displacement on the other hand speed is a scalar quantity.
