Suppose that potential customers arrive at a single$-$server bank in accordance with a Poisson process

having rate $.$ However, suppose that the potential customer will enter the bank only if the server is

free when he arrives. That is$,$ if there is already a customer in the bank, then the customer, rather than

entering the bank, will go home. Assume that the amount of time spent in the bank by an entering

customer is a random variable having distribution $G$ with mean ${}_G$ and variance ${}_G^2,$ then. Find the rate

at which customers enter the bank?

A$.\frac{1}{{}_G+1}$

B$.\frac{}{.{}_G+1}$

C$.\frac{1}{{}_G+1}$