The dish made with raw bananas, drumsticks, beans, and cooked in coconut milk is Avial. It is a popular vegetable preparation in South Indian cuisine, especially in Kerala and Tamil Nadu.
- Poriyal is a dry vegetable dish, usually made with coconut, but it does not involve coconut milk.
- Variyal is a type of vegetable dish that is stir-fried but is different from Avial in terms of ingredients and preparation.
- Undhiya is a Gujarati dish, typically made with various vegetables, but it does not involve coconut milk.
Thus, the correct answer is Avial.