Oklahoma requires agency disclosure:

Option A is incorrect because agency disclosure in Oklahoma must occur before providing brokerage services, not at closing. Waiting until closing would violate the state's requirement that clients understand their agency relationship before any substantive services are rendered. This timing ensures clients can make informed decisions about representation throughout the transaction process, not just at the end when significant decisions have already been made.

Agency disclosure is not optional in Oklahoma; it's a mandatory requirement that must be provided, not just when requested. This option incorrectly suggests disclosure is discretionary rather than legally mandated.

Oklahoma law specifically requires agency disclosure, so option D is factually incorrect. This option would only be true in states with different regulations, but Oklahoma has clear requirements for agency disclosure.