Final answer:
The Speaker of the House influences policy-making by appointing committee chairpersons, who wield power over committee activities and the legislative agenda.
Step-by-step explanation:
The Speaker of the House wields considerable influence in the policy-making process through the selection of committee chairpersons. Under statement B, it is accurate to say that the Speaker has the authority to appoint committee chairpersons. This ability allows the Speaker to strategically influence the legislative agenda, oversee committee activities, and consequently shape policy outcomes. Committee chairs are powerful figures who have control over important committee functions, such as budgeting, scheduling meetings and hearings, and deciding which bills will be considered. With the selection power, the Speaker can thus assemble committees that align with their legislative priorities, fortifying the majority party's agenda and affecting the passage of legislation.