Assertion (A): Vehicular emissions are a dominant source of urban air pollution in Indian megacities. Reason (R): High vehicle density, traffic congestion, and frequent cold starts increase emission rates. Choose the correct option:

Consider the following statements about Particulate Matter (PM): (i) It is a mixture of solid particles and liquid droplets found in the air. (ii) Dust from construction sites and unpaved roads is a major source of PM. (iii) Overexposure to PM can lead to severe respiratory disorders. Which of the statements given above are correct?

Atmospheric haze, which limits visibility in urban and industrial environments, is primarily caused by which of the following?