Step 1: Understanding the Concept:
The described condition is Elephantiasis (Filariasis).
Step 2: Detailed Explanation:
Elephantiasis is caused by filarial worms like Wuchereria bancrofti.
These worms reside in the lymphatic vessels of the lower limbs.
They cause chronic inflammation and blockage of these lymph vessels, which leads to massive swelling and accumulation of lymph fluid in the tissues.
Step 3: Final Answer:
The most likely cause is the blockage of lymph vessels. Option (c).