Jill Jackson hired Todd Taylor as her agent to purchase $1,000$ shares of XYZ stock on her behalf. Jackson did not know that Taylor owned $1,000$ shares of XYZ stock that he wished to sell. Taylor sold these $1,000$ shares of XYZ stock to Jackson slightly above market price, without notifying Jackson that he was the seller of the stock. Taylor's purchase of his stock on behalf of Jackson was

an act that terminated the agency relationship.

a breach of the duty of loyalty.

a breach of the duty of performance.

a breach of the duty of accountability.

a breach of the duty of notification.