Final answer:
Andrea Ghez credits majoring in physics for giving her the opportunity to do exciting research for NASA-related projects.
Step-by-step explanation:
Andrea Ghez credits majoring in physics the most for giving her the opportunity to do exciting research for NASA-related projects. During her undergraduate years, she changed her major multiple times, but it was as a physics major that she became involved in astronomical research and had the opportunity to do actual observing at observatories in Arizona and Chile.