Joelle is a manager at a construction company, and she is interested in the chemistry behind the materials they use. She has begun studying the materials used to fill walls. She knows that to keep the temperature inside a room steady the material must be a thermal insulator, and she predicts that materials should not be acidic or else they would dissolve too easily in water. Which of these is a molecular ingredient that could be used in a wall-filling material ?

C6H6
Na6Ba6
NeNa
HCl