Final answer:
Edison's association with the electric chair backfired by tying his name to gruesome executions. This attempt did not prevent the adoption of AC power, which enabled factories to operate longer and contributed to urban growth.
Step-by-step explanation:
Thomas Edison's attempt with the electric chair backfired on him because c) the public associated Edison with gruesome executions. In his efforts to discredit alternating current (AC) power, which was being promoted by George Westinghouse, Edison suggested that AC power would be ideal for the electric chair, believing this association would deter the public from adopting AC power for domestic use. However, this strategy ultimately resulted in Edison's name being tied to the negative image of the electric chair and executions, rather than thwarting the adoption of AC power, which became the dominant electrical system despite Edison's attempts.
An important result of electrifying the workplace, according to the provided information is b) It enabled factories to stay open later and people to work at night. The introduction of electric lighting extended factory working hours and increased productivity, leading to a greater demand for workers and contributing to the growth of urban centers.