Answer:
.b. When she returned to work after maternity leave, she learned that her office had been relocated to the second floor
Explanation:
The above statement correctly punctuated with a comma after the brief stop in "maternity leave". Commas and punctuations in general offer meaning to statements, and aid easier comprehension. The comma in the above statement for example makes it easier to understand the sequence in events such as that she first returned to the office before the subsequent event took place.
C the roman economy would not have prospered if it were not for the roads in the empire
B. The framers wanted to ensure that a single branch couldn't be too powerful, so they created checks and balances so the branches could stop each other from doing whatever they wanted.