ANSWER ASAP PLS 50 POINTSS ;) ;)

Answer:
I would say D) A new substance is formed with different properties.
It doesn't nesisarally have to have a specific change (except mass), but it could be a wide variety of changes.
Answer:
A New substances form with different properties
Explanation:
When two different chemical substances are combined, they form new substances with different properties. The properties may be modified and the substance formed may exhibit better characteristic than individual properties of its components. For example, when sodium and chlorine combine, they form sodium chloride. Sodium chloride has different properties than any of the constituents.