Which power does the Constitution specifically deny to the federal
government?

Constitution neither grants exclusively to the federal government nor denies to the states. Example: establish court systems, make and enforce laws, collect taxes to pay the costs of governing , and borrow and spend money.

The power to pass laws retroactively, or the power to ratify changes to the Constitution. Answers could vary

Explanation:

The power to pass laws retroactively:

The Federal government cannot pass laws retroactively, meaning they cannot pass laws that legally change consequences from past actions. These are called "ex-post-facto-laws". You can find the section about ex-post-facto laws in Article I, Section 9, Clause 3 of the US Constitution.

An example of an ex-post-facto law: Say that a law was created, making it illegal to mow your lawn past 5pm. Anyone who has ever mowed their lawn past 5pm, in the history of mowing your lawn past 5pm, would have to be arrested.

The power to ratify changes to the US Constitution:

To ratify, or to accept/approve, the Constitution is a power granted to by state legislatures, but not to the federal government. This is to prevent giving the federal government too much power.

Congress must propose an amendment that has a ⅔ majority vote by both the Senate and the House of Representatives before it can be sent to state legislatures. After that, the amendment can only become valid when ¾, or 38 out of 50 states, ratify it. You can find this in Article V of the US Constitution.

i think it should be slowed colonial western march

the answer wold be b) travel among nations should be regulated by an international organization