Final answer:
Arcturus is not another name for the constellation Ursa Minor, which is what Arcas became. It is a star in the Boötes constellation.
Step-by-step explanation:
The constellation that Arcas became is known as Ursa Minor, which is not another name for Arcturus or Boötes. Ursa Minor is often called the Little Dipper due to its resemblance to a smaller version of the Big Dipper, which is a part of the Ursa Major constellation. Ursa Minor includes the Polaris star, also known as the North Star.
The answer to the student's question is: c. Arcturus. Arcturus is a star in the constellation Boötes, which is separate from Ursa Minor. The other options, a. the Great Bear (another name for Ursa Major), and b. the Little Bear (another name for Ursa Minor), are related to Arcas's constellation, while d. Boötes is the constellation that contains Arcturus.