Answer: b. 3,2, 1,4
3. Allport, GW. (2001). Introduction. In S. Akhilananda, Hindu psychology: Its meaning for the West (pp. ix.x). London. England: Routledge. (Original work published 1948)
2. Allport, G.W. (1979). The nature of prejudice (25th anniversary ed.). Cambridge, MA: Addison, Wesley. (Original work published 1954)
1. Allport, G. W. (1930-1967). Correspondence. Gordon W. Allport Papers (HUG 4118.10), Harvard University Archives, Cambridge, MA.
4. Allport, G.W., & Ross, M. J. (1967)IPersonal religious orientation and prejudice. Journal of Personality and Social Psychology, 5, 432-443.
Explanation:
In APA referencing style, authors are listed in alphabetical order.
When citing works by the same author(s), list works in an order that depends on the year of publication. This also applies to works published in the same year. You can add a, b, c, etc to the year to show the order they were published if they are in the same year.
The reason 3 and 2 come before 1 and 4 is due to their original publication dates which are earlier than those of works 1 and 4.