TOEFL Listening: TPO-TOEFL阅读TPO - K5VSLFU41YAK8U23N$

What can be inferred from paragraph 3 about Cuicuilco prior to 200 B.C.? A. It was a fairly small city until that date. B. It was located outside the Valley of Mexico. C. It emerged rapidly as an economical and political center. D. Its economy relied heavily on agriculture.