An option listing agreement where the broker purchases the property from the seller, and then resells the property making a profit on the resale requires?

This is the correct answer because option B follows the ethical principle of full disclosure to the principal and obtaining their permission before proceeding with the resale. Option A would be unethical as it does not disclose the profit to the seller. Option C is incorrect because brokers still have obligations and responsibilities even if they assume risks. Option D is incorrect because private disclosure to regulatory authorities is not enough to fulfill the ethical obligation of informing the principal.