Final answer:
The Speaker of the House signs the certificate that accompanies flags purchased by constituents when flown over the Capitol.
Step-by-step explanation:
The correct answer is B) The Speaker of the House.
When constituents arrange to purchase flags flown over the Capitol, each flag is accompanied by a certificate signed by the Speaker of the House. The Speaker of the House is the presiding officer of the United States House of Representatives and is responsible for managing and organizing the legislative process.
For example, if a constituent contacts their representative in the House of Representatives to purchase a flag, the Speaker of the House will sign the certificate that accompanies the flag.