Which unit would be used to measure the amount of matter in an object?

Typically Grams or Kilograms are used to measure mass. On an atomic scale you would use Au for measuring atoms.

The correct answer among the choices given is the second option. Matter most likely is the title of her notes. Matter makes up everything. It can be solid, liquid, or gas and is made up of atoms or tiny particles that are known to be the smallest unit of matter.