Broker Linda obtains a listing from a seller that she has never previously worked with. However, when she tells Mel, her designated broker, about it$,$ Mel says that he's had bad dealings with that seller before and tells Linda to cancel the listing. Which of the following statements is true?

$1-$ Linda may keep working with the seller, but under a heightened level of scrutiny from her managing broker

$2-$ Linda may keep working with the seller if she feels confident about doing so

$3-$ Linda must renounce the listing, because it belongs to the brokerage, not to her

$4-$ Linda must renounce the listing if the seller has previously been convicted of criminal fraud