Which of the following is not a qualification to be Speaker of the House?

The qualifications to be Speaker of the House are largely based on the requirements to serve as a member of the House of Representatives. While the Speaker must be a U.S. citizen and have resided in the U.S. for at least seven years, the minimum age to be elected as a House member is actually 25 years old. However, being the Speaker does not require an individual to meet the age requirement of being 25 at the time of their election, but rather they must already be an elected member. Therefore, the requirement to be "at least 25 years old" does not directly apply to the qualifications of the Speaker beyond the context of being elected as a member of the House.

In contrast, the other qualifications listed align with the rules for being a member of the House itself, making them applicable to the role of Speaker as they are necessary for one to hold that position. Thus, the age requirement is not formally a separate qualification for the role of Speaker beyond that of being a member.