The correct option is A It is defined as the number of females per 1000 males in a given population.
To compare the number of males and females in a society, we use the concept of sex ratio. It is defined as the number of females per 1000 males in a given population. In a society that treats males and females equally, the sex ratio is close to 1:1 or 1000 females for every 1000 males.