Registered representative Susan Smith is recommending that a client exchange one deferred variable annuity for another. She has asked the client whether or not he has made an exchange at your firm in the past $36$ months. Susan must also make a reasonable effort to determine if the client has

A$)$

purchased any mutual funds from your firm in the past $36$ months

B$)$

exchanged a deferred variable annuity at any broker$-$dealer in the past $5$ years

C$)$

exchanged a deferred variable at any firm in the past $36$ months

D$)$

exchanged a deferred variable annuity at any broker$-$dealer in the past $10$ years