Answer:
(b) gas and dust
Explanation:
"The interstellar medium is the stuff between the stars. Made up mostly of hydrogen and helium gas – plus trace amounts of ices, silicate grains, and all the other elements – it contains all the material needed to make stars and planets. It is shaped by stellar winds, dying stars, galactic magnetic fields, and supernova explosions."
"The interstellar medium is filled primarily with hydrogen gas. A relatively significant amount of helium has also been detected, along with smaller percentages of such substances as calcium, sodium, water, ammonia, and formaldehyde . Sizable quantities of dust particles of uncertain composition are present as well."
Science, a system of knowledge.
Here we have to point out the necessary character of the substance needed which are used as lightning conductor.
The substance should have the following properties:
High electricity carrying capacity and less resistant.
High melting point
The substance should have high electricity carrying capacity or the resistance is less so that the electricity generated during the lightning easily conducted to the ground
The substance should have high melting point so that during lightning the generated high temperature cannot disrupt the material.