GMAT Sentence Correction (SC) | Re: After serving an apprenticeship in Birmingham, Darby started a

After serving an apprenticeship in Birmingham,Darby started a business in Bristol, but he had moved to Coalbrookdale in 1710 with an idea that coke derived from coal could provide a more economical alternative to charcoal as a fuel for ironmaking.

A. Darby started a business in Bristol, but he had moved to Coalbrookdale in 1710 with an idea that coke derived from coal could provide a more economical alternative

B. a business was started by Darby in Bristol, but then he moved to Coalbrookdale