The most important reason for the collapse of Rome was the failure to actually integrate what they conquered. When Roman soldiers conquered new lands, it was rare that they ever attempted to force their culture, ideals, or laws upon the natives and barbarians. Thus, when the Empire began suffering internal struggles, the natives they had conquered decided to take action, which lead to the swift collapse by barbarian invasion from all sides. It's hard to pick a LEAST important reason, seeing that there were many of them, but I suppose a contender would most likely be the common refusal of the Empire to even acknowledge that barbarians were rising. On the outer edges of their territory, in places like Gaul and Morocco, the Roman government was reluctant to even recognize the threat of the barbarians, thinking that even accepting that these barbarians were causing trouble would weaken their prestige in the public eye.
The answer is d: Ford's revolution of the assembly line to make cars less expensive.
although they saw he invented the assembly line he did not it was in fact Ransom E. Olds who did. all that Ford did was improve it. he put a person to do one thing and that was what they did nothing else. this made it faster as to this had nobody fighting to do the job with the person they were working with.
Come up with something special that your light bulb can do (make something up) then set up an advertisement filming how "helpful" it can be in every day life. You can use people to talk about how great it is within the ad (kind of like an interview.)