"Vanishing Greenery; A Growing Urban Crisis" In most of our cities, rapid urbanisation has led to a significant decrease in greenery over the past two decades. As the population increased, the demand for housing, roads and commercial buildings grew, leading to clearing of parks, gardens, and natural resources. This has contributed to several problems. 
(a) Mention one significant problem caused by the reduction in urban greenery.
(b) How do green plants contribute to improving the air quality?
(c) What role can you, as a citizen, play in protecting urban greenery?
Given below are two statements:
Statement I: Transfer RNAs and ribosomal RNA do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.
In the light of the above statements, choose the most appropriate answer from the options given below: