Im almost sure its C. Hope this helps.
Compounds are represented by chemical formulas.
The correct answer is "Compounds are represented by chemical formulas. "
A chemical formula is a graphic expression of the elements that make up any chemical compound, as well as the numbers and proportions of their respective atoms.
That is, the chemical formulas are made up of chemical symbols that indicate the elements that make up a compound and the number of atoms that each element contributes contains the formula. The latter is indicated by a subscript, that is, a small number that is placed below and to the right of each element that requires it.
Then, the correct answer is "Compounds are represented by chemical formulas. "