Cygnus X-1 and LMC X-3 Are Black Holes If the Masses

Multiple Choice

Cygnus X-1 and LMC X-3 are black holes if the masses of the unseen companions are

A) less than 5 solar masses.
B) more than 5 solar masses.
C) between 0.4 and 1.4 solar masses.
D) less than 0.4 solar masses.
E) not larger than the masses of the stars that we can see.