The Answer would be the Moderator.
Molten glass is malleable and can be shaped through various techniques. From a molecular point of view, glass is an overcooled liquid. The main component of the glass is silica, which is obtained from sand, quartz or flint. The silica melts at very high temperatures to form glass. Due to its high melting point it suffers little dilatation with temperature changes is suitable for laboratory apparatus and telescope mirrors. Glass with high sodium content can be dissolved in water, forming a viscous liquid called water glass used as fireproof varnish and sealant. As it has a high sodium content it is used in the manufacture of spotlights, glasses, bottles and laminated glass. It also results in lead glass that is combined with lead oxide to make lenses, prisms and jewelry. Another type of glass resulting is borosilicate glass that contains borac and is very durable and resistant to high temperatures, is used in kitchen utensils and equipment for chemical processes.
The answer would be D. "Yet, he figured out how to make a battery using soda, metal, and tape."
This shows that Kelvin was creative in solving the problem of having no batteries because he found a way to create his own with rather strange items. Most people wouldn't think to create anything with those three items, which shows that this creation took extra creativity on Kelvin's part.
