As he is checking in Mr$.$ Grant $($a new guest$),$ front desk agent David notices a discrepancy between

the signature on Mr$.$ Grant's credit card and the signature on his registration card. Although the credit

card was approved electronically, David is suddenly suspicious of its validity. What should he do

first?

Notify security.

Request additional identification.

Ask Mr$.$ Grant if the credit card is really his.

Inform the general manager.