Stella Wants to Give Her Baby the Best Start During

Stella wants to give her baby the best start during prenatal development, so she is researching the latest findings on nutrition and teratogens. She's frustrated because the findings on caffeine:

A) have been mixed on whether it has ill effects.
B) have demonstrated no ill effects, but everyone says to avoid it anyway.
C) have demonstrated substantial ill effects.
D) hardly exist because no one is studying it.