In December 2001, a British Man with Ties to the Al-Qaeda

In December 2001, a British man with ties to the Al-Qaeda terrorist group was on a flight from Paris to Miami when he tried to set off a bomb, one built into his shoe.Even though his attempt failed, his actions had an immediate effect on air travel in the United States: to board a flight, the U.S.Transportation Security Administration (TSA) , a division of the cabinet-level Department of Homeland Security (DHS) , soon began requiring most passengers to take off their shoes while in a security line, and have them scanned for explosives.The TSA could call in law enforcement to question or detain people who refused screening because the rule had the force of law.Why was this likely the case, from what you have read about how the federal bureaucracy works?

A) After the shoe-bombing attempt, Congress passed a law that required all passengers, from children to the elderly, to take off their shoes while in a security line.
B) Congress granted the DHS and TSA rule-making and regulatory authority in the airline security arena.
C) Presidents worked closely with the TSA to make sure that shoe screenings were mandatory, issuing executive orders to begin the practice and keep it going.
D) The TSA, as a clientele agency, lobbied federal, state, and local elected officials, on the airlines' behalf, to enact shoe-screening requirement laws nationwide.