Final answer:
The last viable crop in the movie Interstellar was wheat. Therefore, the correct option is b. Wheat.
Step-by-step explanation:
The last viable crop in the movie Interstellar was wheat.
Wheat is a staple crop that originated in the Fertile Crescent, which is a region stretching from the Persian Gulf to the eastern Mediterranean. It was cultivated by civilizations like Egypt and Mesopotamia thousands of years ago. In the movie, due to an environmental crisis, wheat becomes the last viable crop for human survival.