What kind of star is characterized as a Red Variable Star?

A Red Variable Star is typically identified by its changes in brightness and its reddish coloration. V838 Monocerotis, which is option B, is known for its dramatic outbursts and variability in brightness, making it an excellent example of a Red Variable Star. The star experienced a significant outburst in 2002, increasing its brightness dramatically and becoming one of the brightest stars in the Milky Way temporarily.

This type of variability is characteristic of certain types of red supergiants and other late-stage stellar objects. These stars often undergo pulsations or eruptions due to their turbulent atmospheres and advanced stages of stellar evolution.

In contrast, the other options represent different kinds of astronomical objects or phenomena. Cygnus X-1 is known as a black hole binary system, while M1, also known as the Crab Nebula, is a supernova remnant. SXP 1062 is a particular pulsating X-ray source, not a red variable star. Thus, V838 Mon's characteristics as a Red Variable Star distinctly support its classification in this context.