Any real estate broker licensed under the provisions of this chapter who engages in the real estate business, as defined in § 20-311, shall retain the following records for a period of not less than seven years after any real estate transaction closes, all funds held in escrow for such transaction are disbursed or the listing agreement or buyer or tenant representation agreement expires, whichever occurs later: (1) All purchase contracts, leases, options, written offers or counteroffers drafted by such broker or on behalf of such broker; (2) the listing agreement or buyer or tenant representation agreement, any extensions of or amendments to such agreements and any disclosures or agreements required pursuant to sections 20-325a to 20-325l, inclusive; and (3) all canceled checks, unused checks, checkbooks and bank statements for any escrow or trust account maintained pursuant to § 20-324k. Such records may be retained in any format, electronic or otherwise, capable of producing an accurate copy in paper format of the original document.