Which of the following is a Constellation?

Orion is a constellation. 
A constellation is a group of stars making some picture or pattern in space, which we can see at night time. So, for example, in the above question, Orion is a constellation. And we have found at least 88 constellations. And apart from Orion, Ursa Major, Ursa Minor, Leo, and Cassiopeia, they are also commonly known constellations.
Hence, the option "Orion" is correct.