A Catalogue Company That Receives the Majority of Its Orders

Multiple Choice

A catalogue company that receives the majority of its orders by telephone conducted a study to determine how long customers were willing to wait on hold before ordering a product.The length of time was found to be a random variable best approximated by an exponential distribution with a mean equal to 2.8 minutes.
-What is the probability that a randomly selected caller is placed on hold fewer than 7 minutes?

A) 0.9990881
B) 0.917915
C) 0.0009119
D) 0.082085