What level of structural organization do voltage-gated sodium channels in muscle sarcolemma represent? what level of structural organization do voltage-gated sodium channels in muscle sarcolemma represent? cellular organ molecule tissue?

The correct answer is a molecule.  

It is relevant to consider the compositions of the body in terms of basic levels of the organization, which enhance in complexity: subatomic particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms, and biosphere.  

The voltage-gated sodium channels come under the molecule level of structural organization. It plays an essential role in action potentials.