FINRA Rule $2090$ is designed to do all of the following except

A$)$

require members to "know their customers"

B$)$

have members obtain and retain the essential facts concerning each customer.

C$)$

require members to use reasonable diligence in regard to the opening and maintenance of every customer account

D$)$

expect members to have a reasonable basis to believe that a series of recommended transactions are not excessive and unsuitable for the customer in light of the customer's investment profile.