You are answering a USMLE-style medical question. Question: A 26-year-old gravida 2 para 1 at 24 weeks gestation is admitted to the labor and delivery suite with mild abdominal cramps, uterine contractions, and a watery vaginal discharge. She has a history of preterm birth. The vital signs are as follows: blood pressure 125/80 mm Hg; heart rate 100/min; respiratory rate 13/min; and temperature 36.6℃ (97.9℉). The pelvic examination reveals cervical softening and shortening. Transvaginal ultrasound shows a cervical length of 12 mm, which is consistent with preterm labor. A tocolytic and a single dose of betamethasone are administered. Betamethasone stimulates which fetal cells? Options: A) Goblet cells B) Bronchial epithelial cells C) Type II pneumocytes D) Vascular smooth myocytes Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.