which type of star will become a black hole when it dies?\n○ a protostar\n○ a supergiant\n○ a white dwarf\n○…

Brief Explanations:

Supergiants are massive stars. When they run out of fuel and die, their cores can collapse under their own gravity to form black - holes. Protostars are in the early stage of star formation, white dwarfs are the remnants of low - to medium - mass stars and are too low in mass to form black holes, and red dwarfs are small, long - lived stars that also do not have enough mass to become black holes.

Answer:

a supergiant