The vegetation of savannah consists of grassland with scattered small trees, but extensive areas have no trees. The forest development in such areas is generally kept in check by one or more or a combination of some conditions.
Which of the following are conditions?
Select the correct answer using the code given below.
(a)
1 and 2
(b)
4 and 5
(c)
2, 3 and 4
(d)
1, 3 and 5