<prompt> A newborn baby has a head circumference of 35 ems. at bih, His optimal head circumference will be 43 ems at -4 months of age6 months of age8 months of age12 months of age  <response>: Ans. is b i.e., 6 months of age o At 6 month of age head circumference is between 40.0-43.5cm. 