L What is the function of the Executive Branch of the government in terms of the affect it has on the lives of American citizens?

To implement the legislation.

Explanation:

After the legislative branch create the laws, they need an organized effort to implement the laws for the people. This require the use of government for hiring workers, buy the necessary infrastructures, and collected feedback from the people.

Executive branch of the government is the want that make this organized effort.  They created several department or agencies that's focused on specific expertise to carried out the plan.