Which Sentence Is Punctuated Correctly

Which sentence is punctuated correctly?

A) Many employees will be facing layoffs, in the meantime, some are seeking retraining through the company's strong educational incentive.
B) Standardized tests are often used by schools to measure student success; however, they are often criticized as discriminating against minorities.
C) Our Los Angeles office will be closing, therefore; employees must either retire, transfer to another branch, or accept a severance package.