The source of implied powers under the u. s. constitution is the clause. a. necessary and proper b. comity c. supremacy d. full faith and credit e. commerce

The correct answer is A. Necessary and proper

The necessary and proper clause, also called the elastic cause, is part of Article 1 of the United States Constitution. This clause essentially states that even though a power may not be explicitly given to the president, some powers can be assumed or implied. This clause is seen in US history in several instances including:

1) When Thomas Jefferson bought the Louisiana Purchase from France.
2) When George Washington created the First Bank of the United States.

D.successful because there were no legal protections for unions.