What is a Sex ratio–

Correct option is B

Sol. Sex ratio is defined as the number of females per 1000 males in the population. It is a key demographic indicator of gender balance in a society. In India, the sex ratio is monitored closely due to historical preference for male children and gender-based practices. A low sex ratio often indicates gender bias, female foeticide, or neglect of girl children.
Explanation of each option:
· (a) Number of Males and Females in 1000 population – Incorrect. This describes general population composition, not the sex ratio specifically.
· (b) Number of females per 1000 males – Correct. This is the standard demographic definition of sex ratio used in Census and surveys.
· (c) Number of males per 1000 females – Incorrect. This is the reverse ratio and is not the standard definition used in Indian or global statistics.
· (d) Number of female birth per 1000 male birth – Incorrect. This refers to child sex ratio at birth, which is different from overall sex ratio.