The correct answer is Mercury
Explanation:
In a circular object or spherical object such as a planet, the diameter is calculated by drawing a straight line from one side of the sphere to the other. This measure is the double of the radius (distance from the center to any side). In the case of planets, these differ not only in properties but also in size, which makes them have different diameters.
For example, the diameter of Earth is approximately 12,700 km, while the diameter of Jupiter (the largest planet) is almost 143,000 km. In this context, the planet with a diameter that is approximately the same that the distance from one coast to the other in the U.S. is Mercury because the diameter of this planet is almost 4879 kilometers and the distance from the West coast to the East coast is approximately 4828 kilometers, although this distance varies depending on the location.