The birth weight of the baby doubles at the age of–

Correct option is B

Sol. A healthy infant typically doubles their birth weight by 5–6 months of age and triples it by 12 months. This is a key indicator of optimal growth and nutritional status. If weight gain is delayed, it may indicate feeding problems, malnutrition, or underlying illness requiring evaluation.
Explanation of each option:
· (a) 3 months – Some rapid growers may reach 1.5× birth weight by this time, but not double.
· (b) 6 months – Correct Answer. Most infants are expected to weigh twice their birth weight around this age, under normal growth conditions.
· (c) 9 months – By this age, weight gain continues steadily but would exceed double for many.
· (d) 12 months – At 12 months, the baby’s weight is expected to be nearly triple the birth weight, not just double.