Huge Fluxes of X-Rays Are Detected from the Direction of Cygnus

Multiple Choice

Huge fluxes of X-rays are detected from the direction of Cygnus X-1 with a spectrum that looks similar to that of a blackbody with a peak wavelength of 1.45 nm (1 nm = 10^-9 m) . These X-rays are probably emitted by matter being heated as it falls into a black hole. What is the temperature of this gas?

A) 2 * 10⁶ K
B) 4205 K
C) 2 * 10^-2 K
D) 2* 10⁴ K