Ada is a traditional sweet made with rice dough, filled with a sweet filling, and steamed in banana leaves, typically found in Kerala.
- Modak is a Maharashtrian sweet, similar in appearance but usually made with rice flour and filled with coconut and jaggery.
- Puran Poli is a Maharashtrian flatbread stuffed with a sweet lentil filling, not made with rice dough.
- Basundi is a milk-based dessert from Gujarat, not made with rice dough or banana leaves.
Thus, the correct answer is Ada.