Consider the following statements in respect of effect of air pollutants on vegetation:1. Necrosis refers to killing of tissue2. Chlorosis refers to loss or reduction of green plant pigment3. Leaf abscission refers to the dropping of leaves4. Leaf epinasty refers to a downward curvature of a leaf due to a higher rate of growth on the upper surfaceWhich of the above statements are correct?

• A. 1, 2 and 3 only
• B. 1, 2, 3 and 4
• C. 2, 3 and 4 only
• D. 1, 2 and 4 only