which of the followwing are powers kept by the federal government under the federal system of the government in the United states?

Under the federal system of government in the United States, the powers kept by the federal government are known as **enumerated powers** (option a). These are specifically listed in the U.S. Constitution, primarily in Article I, Section 8.

Here's a brief explanation of the other options:

- **Executive powers** (option b) generally refer to the powers of the executive branch, primarily the President, but this term is not specifically used to describe powers reserved to the federal government as a whole.
- **Reserved powers** (option c) are powers that are not specifically granted to the federal government and are kept by the states, as outlined in the Tenth Amendment.
- **Concurrent powers** (option d) are powers that both the federal government and the state governments can exercise, such as taxation or the ability to borrow money.

So, the correct answer is **a. enumerated powers**.