Which chemical formula indicates the presence of more than one element?

The presence of more than one element in a chemical formula is indicated by the combination of different chemical symbols. In the provided formulas:

NaH consists of sodium (Na) and hydrogen (H), clearly indicating two different elements.

SiO2 includes silicon (Si) and oxygen (O), representing another combination of distinct elements. The presence of the subscript “2” signifies that there are two oxygen atoms for every silicon atom, but it does not change the fact that there are two types of elements.

K2O consists of potassium (K) and oxygen (O). The subscript "2" indicates there are two potassium atoms paired with one oxygen atom, illustrating the presence of different elements.

Given that all three formulas contain more than one element, the choice indicating that all options reflect this characteristic is indeed correct. Each formula distinctly includes a combination of at least two different elemental species, validating the answer that all of the choices represent compounds containing multiple elements.