The correct option is The Godavari.
Explanation
The epithet 'Dakshin Ganga' (Ganga of the South) is assigned to the Godavari river primarily due to its size, extensive catchment area, and length, which are comparable within the Peninsular context to the river Ganga in the Himalayan system.
Detailed Analysis
- The Godavari: It is the largest river system in Peninsular India and the second-longest river in India after the Ganga. Due to its massive size, length (1,465 km), and age, it is widely known as 'Dakshin Ganga' or 'Vridha Ganga' (Old Ganga).
- The Kaveri: While the Kaveri is also culturally significant and often referred to as the 'Ganga of the South' (specifically Dakshin Bharat ki Ganga) due to its religious sanctity and perennial flow, standard geographical specifically attribute the title 'Dakshin Ganga' to the Godavari.
- The Krishna and The Mahanadi: These are major Peninsular rivers but do not carry this specific geographical epithet.
Key Takeaway: The Godavari is called 'Dakshin Ganga' because of its length and area. The Kaveri is often called the 'Ganga of the South' due to its religious significance and perennial nature.