Final answer:
The U.S. Customs and Border Protection (CBP) agency, under the Department of Homeland Security, is responsible for protecting U.S. ports of entry and managing border security and immigration.(option a)
Step-by-step explanation:
The U.S. federal agency that protects the U.S. ports of entry is U.S. Customs and Border Protection (CBP). This agency is a part of the Department of Homeland Security and is responsible for immigration and border security including the management of land borders and ports, which are crucial for preventing irregular migration and dismantling organized criminal networks. Their duties extend to ensuring that the borders remain secure from various threats, including terrorism, while facilitating lawful international travel and trade.
Following the terrorist attacks on September 11, 2001, there has been a significant focus on improving border security. CBP works to protect the United States by enforcing immigration laws, preventing illegal immigration, and promoting safe legal pathways of migration. Additionally, they contribute to the safety and security of American communities by combating the smuggling of narcotics, weapons, and other contraband.