Which best describes the Rho Ophiuchi cloud complex?

The Rho Ophiuchi cloud complex is best described as a dark nebula with a red supergiant. It is one of the closest and most well-studied star-forming regions in the Milky Way, characterized by dense, dark clouds of gas and dust. The complex is particularly notable for containing a rich collection of protostars and young stellar objects, as well as the prominent red supergiant star Antares, which is part of the neighboring Scorpius constellation.

Dark nebulae, such as Rho Ophiuchi, are significant in astronomy as they are often the sites of star formation, obscuring the light from objects behind them due to their high concentrations of dust and gas. The presence of a red supergiant within this context highlights the stellar life cycle and the evolution of massive stars, making the complex an essential area of study for understanding the processes that govern star formation and the lifecycle of stars in general.