Final answer:
William most likely holds a real estate license to help Shannon find a studio apartment.
Step-by-step explanation:
The license that William holds to help Shannon find a studio apartment is most likely a real estate license. A real estate license is required to assist in the buying, selling, and leasing of properties, including apartments. This license allows professionals to provide services such as property search, negotiation, and transaction management.
With a real estate license, William can legally help Shannon find the perfect apartment and earn a fee for his services. This license ensures that William has the necessary knowledge and skills to navigate the real estate market and assist clients in their property search.