Correct answer: (d) A and B
Explanation
- A
Only A
(a) Only A. Crude birth rate alone is fertility, not natural increase; deaths must enter. It is not the key.
- B
Only C
(b) Only C. Migration is a component of actual growth, not of natural growth. It is not the key.
- C
B and D
(c) B and D. Death rate without births is not natural increase, and marriages are a nuptiality measure, not the growth residual.
- D
A and B
(d) A and B. Natural growth (natural increase) is crude birth rate minus crude death rate. Migration is excluded by definition. That stored pair is the official key.
Summary. Official key is (d) A and B. Natural population growth uses CBR and CDR only. Migration makes actual or migratory growth; marriages are not a growth residual. Neighbouring terms are NIR, TFR and replacement level 2.1. Honour A and B for this paper.