The main function of the executive branch is to a. carry out and enforce laws and policies
b. write and pass new national legislation
c. increase the size of the bureaucracy
d. select who will serve as president

a. carry out and enforce laws and policies.

Explanation:

the legislative branch writes and passes new national legistlation, c doesn't make sense and the people select the president. the answer is probably a.

the difference is that white collar worker performs skills like worker as a scientist or well blue collars do physical work and they do services like being a cook.

both include an amendment process.