Which of the following would be considered a compound?
He
CI
NaCl
B

NaCl

Explanation:

because He which is helium gas its an element alone,

Cl which is chlorine is a single element,

B which is Boron and its a single element,

but NaCl which is simply called table sugar is the combination between Na, sodium and Cl, chlorine , so its called a compound not an element.

i wish i could but this one is weird give me abc and i can solve it.