If XXX is a discrete random variable where P(X=k)=e−22kk!P(X=k) = \frac{e^{-2} 2^k}{k!}P(X=k)=k!e−22k for k=0,1,2,…k = 0, 1, 2, \dotsk=0,1,2,…, what is P(X≤1)P(X \leq 1)P(X≤1)?
2e−22e^{-2}2e−2
3e−23e^{-2}3e−2
e−2e^{-2}e−2
4e−24e^{-2}4e−2