Your answer of martial law is incorrect because martial law refers to the imposition of military rule by a government, usually in response to an emergency or during times of war. The passage does not mention any emergency or war situation in which the governor of Georgia's order would be considered martial law.
The correct answer, sexism, is derived from the fact that the governor of Georgia insisted that only Georgia officers should command Georgian troops. This indicates a bias or discrimination based on sex or gender, as the governor is specifically favoring male officers from Georgia to hold commanding positions over troops from the same state. This action demonstrates a form of sexism, as it denies the opportunity for female officers or officers from other states to take command.
In summary, the governor's order in the passage is an example of sexism because it shows a preference for male officers from the state of Georgia over others, limiting opportunities based on gender.