The correct answer is: b) Religious offerings.
A xorai is a traditional Assamese bell-metal object used for religious offerings. It is a small, round dish with a handle, and is often decorated with intricate designs. Xorai are used to hold offerings of food and flowers to deities, and are also used in rituals and ceremonies.
Option a) is incorrect because xorai are not typically used for ornamental purposes. They are used for religious purposes, and are not typically displayed as decoration.
Option c) is incorrect because xorai are not typically used for serving food. They are used for religious offerings, and are not typically used to serve food to people.
Option d) is incorrect because xorai are not typically used as musical instruments. They are used for religious offerings, and are not typically used to make music.