which type of star will become a black hole when it dies?\no a protostar\no a supergiant\no a white dwarf\no…

Brief Explanations:

When a supergiant star runs out of fuel and collapses under its own gravity, it can form a black - hole. A protostar is in the early stage of star formation, a white dwarf is the remnant of a low - to medium - mass star, and a red dwarf is a small, low - mass star that will never become a black hole.

Answer:

a supergiant