I think the answer is A?

Ascientist performs an experiment where she measures the mass of a piece of metal, pours acid onto the metal, washes the metal, and then re-measures the mass of the metal. the scientist repeats the experiment several times, each time increasing the amount of acid used. the dependent variable in the experiment is the: initial mass of the metal final mass of the metal amount of acid used washing the metal

What british actions lead to the creation of the constitution

1. america's first national road morse 2. joined lake erie with the hudson river cooper 3. steam-driven locomotive erie canal 4. allowed businesspeople to keep in touch with trends cumberland 5. telegraph code fulton 6. clermont telegraph