Time Between Consecutive Arrivals of Customers to a Grocery Store $e^{-6}$

Multiple Choice

Time between consecutive arrivals of customers to a grocery store is exponential with a rate of 3 per minute. What is the probability that a time of 2 minutes will elapse between the arrivals of two consecutive customers?

A) $e^{-6}$
B) $e^{-3}$
C) $1-e^{-6}$
D) $1-e^{-3}$