Final answer:
The broker violated the law by failing to waive the commission on property purchased for his/her own account.
Step-by-step explanation:
The correct statement is: c) The broker violated the law by failing to waive the commission on property purchased for his/her own account.
The broker's actions in purchasing the property for themselves and then reselling it to the buyer for a profit violated the law because they failed to waive the commission on the property they purchased.
By not waiving the commission, the broker prioritized their own financial gain over promoting the best interest of their client, the property owner.