Answer:
A. White, solid crystalline powder compound that is fairly stable.
Step-by-step explanation:
When two or more substances chemically react, they form new compounds which properties might be totally different from the original ones.
In this case Sodium, an Alkali Metal, is such the "perfect match" for Chlorine, an Halogen, because Sodium tends to give the electron that Chlorine needs for reaching stability, so they will bond, they will form a new compound, with new properties.
Sodium Chloride is the chemical name for the table salt, which in fact is a white, solid crystalline powder compound that is fairly stable.