Ans. C: Gross reproductive rate The net reproduction rate (NRR) measures the effective feility in a population, taking account not only of bihs but also of the fact that not all women born will survive to their own reproductive years. The NRR is the average number of daughters of reproductive age that a woman would have if she experienced over her lifetime the prevailing age-specific rates of feility and if her daughters experienced the prevailing rates of moality. The gross reproduction rate (GRR) for a paicular year is the average number of daughters that a woman would have if she experienced over her lifetime the age-specific feility rates of that year. In that it refers only to the number of daughters born to women, not the total number of children, it is a special case of the (period) total feility rate; in most circumstances (unless the sex ratio at bih is highly unequal) the GRR equals roughly half the TFR. The general feility rate is similar to the crude bih rate except that it uses a more restricted denominator, the female population of childbearing age, ages 15 to 49. Age-specific feility rates (also called age-specific bih rates) are similar to the crude bih rate but are calculated for specific age groups of women of childbearing age. The range of childbearing ages is conventionally considered to be ages 15 to 49 (sometimes 15 to 44 is used), and a full set of age-specific feility rates would span this interval-usually either in single-year age groups or, more commonly, in five-year groups: 15 to 19, 20 to 24, ..., 45 to 49. Marital feility rates can be calculated either for the full range of reproductive ages (15 to 49 or 15 to 44) or as age-specific rates. The numerator is usually taken as the total number of live-bihs to women in the specified age range, regardless of the marital status of the mother; the denominator is the number of currently married women in the specified age range The total feility rate (TFR) at a given time (technically referred to as the period total feility rate) is the average number of children a woman would bear in her life if she experienced the age-specific feility rates prevailing at that time.