The gases cast off by a dying star are called a. dark matter. b. neutron clouds. c. planetary nebulae. d. remnants.

C. Planetary nebulae

Explanation:

“ Planetary nebula, any of a class of bright nebulae that are expanding shells of luminous gas expelled by dying stars.”

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

3.2x10^7