The correct options are
A Viharas were permanent shelters for monks and nuns.
B Viharas could be made out of wood and bricks, and could even be in caves.
D Monks and nuns in viharas received food and medicines from the local people.
Viharas were permanent shelters for monks and nuns. It could be made out of wood and bricks, and could be even in caves. Land for viharas was donated by rich merchants and traders. Monks and nuns in these viharas received food and medicines from local people.