下列何者可誘發墮胎(abortion)？(1)黃體酮拮抗劑(progesterone antagonist)(2)濾泡刺激素拮抗劑(FSH antagonist)(3)糖皮素(glucocorticoid)(4)雌性素(estrogen)(A)(1)(B)(2)(C)(3)(D)(4)