No entiendo lo que quieres decir
<span>C. Están corriendo is the answer.
There you go.</span>
D: ¿Te gusta vender los collares?
Gustar conjugated is still one word so it cannot be "gust a"
A verb ("vender") is singular so you cannot use "gustan"
A verb after gustar has to be infinitive
so the correct answer is ¿Te gusta vender los collares?
The answer is work and work context.
