Final answer:
The real estate agent should obey the seller client's request for at least two hours' notice before a showing.
Step-by-step explanation:
When a seller client asks for at least two hours' notice before a showing, the real estate agent should obey their request. This is a standard practice in real estate to respect the seller's privacy and ensure that the property is presentable for potential buyers. By giving the seller advance notice, they have time to prepare the house and make it more appealing to potential buyers. It also shows professionalism and respect for the client's preferences.