The correct options are
C A large tract – stretching several kilometres in length and breadth.
D Considerable bio-diversity – where many kinds of plants and animals live and breed naturally without interference.
Most forests have the following features:
1. A large tract - stretching several kilometres in length and breadth.
2. A tree cover and undergrowth (bushes, plants, grasses and creepers) which grow with little interference from human beings.
3. Considerable biodiversity - where many kinds of plants and animals live and breed naturally without interference.