Please use R to solve following question

. 1c. Use Monte Carlo integration to estimate 4 m e 9'L1+m2d'\"' We can consider two importance functions: (:51 is a uniform distribution between 2 and 4; 9152 is a truncated exponential distribution (truncated at 2 and 4). Which of these two importance functions should produce the smaller variance in estimating 0 by importance sampling? Explain and Show numerical evidence