Final answer:
The southern economy did not depend on lots of mountains. Instead, it relied on factors such as fertile soil, a longer growing season, and a warm climate. Therefore, the correct option is D. Lots of mountains.
Step-by-step explanation:
The southern economy did not lean towards dependence on Lots of mountains. Fertile soil, a longer growing season, and a warm climate were all key factors that contributed to the southern economy's dependence.
The fertile soil allowed for successful farming, the longer growing season provided more time for crop production, and the warm climate supported the growth of various crops.