The biologically natural secondary sex ratio at birth in human populations, without any social interference, is approximately:

• A 110 females per 100 males
• B 105 males per 100 females ✓
• C 100 males per 100 females
• D 95 males per 100 females

Explanation

At conception more male embryos are conceived than female, and despite higher male fetal mortality, about 105 boys are born for every 100 girls, giving the natural sex ratio at birth of roughly 105 males per 100 females. Male mortality is higher throughout life, so the sex ratio reverses progressively with age. D value below 100 males per 100 females at birth signals artificial sex selection, as seen in some regions of India, while option A reverses the direction entirely.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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