Pleaseeee urgent answer !!!

A) All questions carry equal marks. Answer ANY THREE of the following questions. Compare and contrast the mechanism of E2 and ElcB reaction. What is the essential feature that is required for an ElcB reaction? B) Show free radical mechanism of monobromination of an ethane for synthesis of ethyl bromide. Why is this method not a good approach for synthesizing an alkyl halide?

c) Briefly discuss the effects of the nature of substrates on SN1 reactivity. Rank the following substances in order of their expected Sv1 reactivity justify in favor of the ranking.