"Black Hole Thermodynamics" explores the concept that:

a) Black holes possess entropy and temperature, related through the Bekenstein-Hawking formula, where the entropy is proportional to the area of the event horizon and the temperature is inversely proportional to the mass of the black hole.
b) Black holes are completely described by their mass and charge alone, with no other observable properties.
c) The laws of thermodynamics do not apply to black holes.
d) The entropy of a black hole decreases over time as it emits radiation.