The third sentence:
Ming and her sister, who is home from college for spring break, organized a bake sale to benefit the victims of the fire.
They both use technology to change the lives of the main characters
The answer is D, "for two weeks". It can be assumed that the word "weeks" applies to a period of time.
Answer A does not specify the number of weeks
Answer B is actually less concise
Answer C is more roundabout than the original statement.
