Final answer:
The recommended weight gain during pregnancy for a woman with a pre-conceptual BMI of 18.0 is approximately 27.5 lbs.
Step-by-step explanation:
The recommended weight gain during pregnancy for a 27-year-old pregnant woman with a pre-conceptual BMI of 18.0 is approximately 27.5 lbs (12.5 kg).
During the first trimester, it is common to gain about 1 lb (0.45 kg) per month. In the second and third trimesters, most women gain around 1 lb (0.45 kg) per week. Taking into account the duration of pregnancy, the recommended weight gain is around 25-35 lbs (11-16 kg) for women with a pre-conceptual BMI of 18.0.
Therefore, option A) 27.5 lbs is the closest to the recommended weight gain.