The correct answers are:
- After invaders took over a society, Muslim traders and merchants worked alongside the Hindu people;
- Once Muslim invaders conquered a Hindu community they used its treasure to build cities and support art;
- Hindus were allowed to continue practicing their religion and though there were tensions, the communities usually managed to learn to live together;
During the early expansion of Islam in South Asia (I believe you meant South not Southeast as there's no Hindus in Southeast Asia), people didn't really had problems between each other based on religion. Most of the people were just doing their jobs and were living alongside each other without any particular problems. The Muslim invaders were not as aggressive as in other places, and there was much bigger religious tolerance, and in general people were not forced to convert to Islam. The treasure of the locals was used for building, creating great monuments, developing cities and infrastructure, as well as developing and supporting the art and science.
