Question

The cloud of interstellar dust and gas that forms a star is known as a

A. white dwarf.
B. protostar.
C. nebula.
D. red giant.

Answer 1

The correct answer is C. The cloud of interstellar dust and gas that forms a star is known as a nebula.

Step-by-step explanation:

A nebula is a section of the interstellar medium that stands out for its radiation or absorption of radiation against the general background of the sky. Previously, any extended object motionless in the sky was called nebulae. In the 1920s, it turned out that there are many galaxies among nebulae (for example, the Andromeda Nebula). After that, the term "nebula" began to be understood more narrowly, in the above sense. Nebulae are made up of dust, gas and plasma.

Answer 2

The answer should be C. - A nebula (from Latin: "cloud"; pl. nebulae or nebulæ, with ligature, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases. As the cloud collapses, the material at the center begins to heat up to form the protostar