The correct option is D) Most of the mills in the Peninsula are located mainly along the east coast.

Peninsular India, also known as South India, is a major sugarcane-growing region in the country. The sugar industry in this region plays a significant role in the agricultural and economic development of the area. Let's analyze each option to understand why option D is incorrect.

a) High yield per hectare of sugarcane:
- The sugarcane cultivation in Peninsular India benefits from favorable agro-climatic conditions, including suitable soil, temperature, and rainfall patterns.
- Farmers in this region employ modern agricultural practices, including the use of high-quality seeds, fertilizers, and irrigation techniques, which contribute to high yields per hectare of sugarcane.

b) Higher sucrose content:
- Sugarcane grown in Peninsular India generally has a higher sucrose content compared to other regions of the country.
- The favorable climate, along with the appropriate variety of sugarcane grown in this region, contributes to the higher sucrose content.

c) Long crushing season:
- Peninsular India experiences a longer crushing season for sugarcane compared to other regions.
- The extended duration is mainly due to the favorable climate, which allows for multiple crop cycles and continuous harvesting.

d) Most of the mills in the Peninsula are located mainly along the east coast:
- This statement is incorrect. The majority of sugar mills in Peninsular India are not located along the east coast.
- In fact, the sugar mills are distributed across various states in the region, including Maharashtra, Karnataka, Tamil Nadu, and Andhra Pradesh.
- These mills are strategically located near the sugarcane-growing regions to minimize transportation costs and ensure efficient processing.

In conclusion, option D is incorrect as most of the mills in Peninsular India are not located along the east coast. The sugar mills are spread across different states in the region to cater to the sugarcane cultivation areas effectively.