Final answer:
If the Sun were to move farther from the galactic center, its orbital speed should decrease due to the effect of differential galactic rotation as stated by Kepler's third law.
Step-by-step explanation:
The question pertains to the rotation speed of the Sun taking into account its location in the Milky Way galaxy. According to Kepler's third law, as objects are farther from the galactic center, they take longer to complete an orbit. Therefore, if the Sun were to move farther from the galactic center, its orbital speed should decrease, because stars in larger orbits move more slowly than those in smaller ones, a phenomenon known as differential galactic rotation. An increase in the Sun's distance from the galactic center would result in a longer orbital period, meaning the Sun would rotate around the center of the galaxy more slowly.