Certainly! Here`s the explanation for the correct match between List I (Mangrove) and List II (State):

A. Achra Ratnagiri - 4. Maharashtra: Achra Ratnagiri is a mangrove region located in Maharashtra state.

B. Coondapur - 1. Karnataka: Coondapur, also known as Kundapura, is a mangrove region situated in the state of Karnataka.

C. Pichavaram - 5. Tamil Nadu: Pichavaram is a notable mangrove forest located in Tamil Nadu state. It is one of the largest mangrove forests in the country.

D. Vembanad - 2. Kerala: Vembanad is a mangrove region found in the state of Kerala. It is home to the Vembanad Lake, which is the largest lake in Kerala and also hosts mangrove ecosystems.

Based on this information, we can match the mangrove regions with their respective states as follows:

A. Achra Ratnagiri - 4. Maharashtra

B. Coondapur - 1. Karnataka

C. Pichavaram - 5. Tamil Nadu

D. Vembanad - 2. Kerala

Therefore, the correct answer is A-4, B-1, C-5, D-2.