Which of the following law(s) is/are given by Ravenstein?
(a) Each main current of migration produces a counter current
(b) Females predominate among short-term migrants
(c) Migration tends to be selective
(d) Magnitude of migration increases with the advancement of technology
Select the correct alternative using the codes below :
1
(a), (b) and (c)
2
(b), (c) and (d)
3
(a), (b) and (d)
4
(c) only