Black – hole is

A black hole is what remains when a very massive star, typically more than about 20 times the mass of the Sun, exhausts its nuclear fuel and collapses under its own gravity. The gravitational pull becomes so strong that not even light can escape past the event horizon, which is why it is called 'black'. So D is correct.

• A (flight recorder): The aeroplane's black box is a recorder of flight data and cockpit voice. It is usually painted bright orange, and the name has nothing to do with astrophysics.
• B (spot on the sun): Sunspots are cooler, darker patches on the photosphere caused by magnetic activity. They are not collapsed matter and are not black holes.
• C (place in Antarctica): There is no geographical feature by this name. Antarctica is a continent of ice sheets and research stations.

The core concept is stellar evolution. Stars above roughly the Chandrasekhar limit (about 1.4 solar masses for the core that remains after collapse, with the neutron star stage giving way to a black hole above roughly 2 to 3 solar masses) end their lives this way. In 2019, the Event Horizon Telescope released the first image of a black hole's shadow in galaxy M87, which is worth remembering for Prelims current affairs. For Mains GS-III, this links to space science and India's astronomy missions.

Trap: Aspirants pick B because sunspots look dark, or they treat the black box in A as a literal black object. Remember that the term refers to a gravitational object, not a colour or a device name.