B. Edison thought that the secret to a better bulb could be found
Explanation:
The first electric bulb was made by Humphrey Davy in 1800. He did experiments with electricity and invented electric battery. He connected a piece of carbon with his battery with wires and saw that the carbon began glowing and produced light. He called it electric arc.
Later English physicist Joseph Swan also invented bulbs but his bulbs were not fit for day to day use because he used carbon filaments in his bulbs that burned quickly.
The bulb invented by Thomas Alva Edison was successful everyday use. He experimented with thousands of different filaments and found that carbon filaments didn't burn and glowed longer if placed in oxygen free bulb. He eventually managed to produce a bulb that glow for more than 1500 hours.
Swan's lightbulb didn't last as long as Edison's and required more current to operate at the same power level as Edison's. Higher current meant you need thicker wire to power it.
