A seller lists a property with a brokerage, sells it himself, and does not have to pay commission. What kind of listing did the seller sign?

In this scenario, the seller signed an exclusive agency listing. This type of listing agreement allows the seller to retain the right to sell the property on their own without owing a commission to the brokerage, as long as the broker didn't facilitate the sale.

In an exclusive agency listing, the seller pays a commission to the brokerage only if the broker finds a buyer for the property. If the seller successfully sells the property independently, the broker does not receive a commission. This distinguishes it from an exclusive right to sell agreement, where the broker earns a commission regardless of who sells the property, including the seller themselves.

The net listing and gross listing options are not common terms referring directly to specific types of listing agreements linked to commission structures or seller rights in the way that exclusive agency does. A net listing usually refers to an arrangement where the seller specifies the amount they want to net from the sale, and the broker keeps any amount over that as commission, while a gross listing is not widely recognized in the context and doesn't reflect a standard real estate practice regarding commission for sellers.

Thus, the correct choice is that the seller must have signed an exclusive agency listing, allowing him to sell the property himself without owing a commission to the brokerage.