When investigators exposed embryos of African clawed frogs to lake-water samples from "hot spots,"
A)many of the tadpoles that developed had deformities.
B)some resulting tadpoles never metamorphosed.
C)the effects could be reduced by adding supplemental thyroid hormone.
D)all of these occurred.
E)none of these occurred.

Question

Quizplus · Accepted Answer

The passage states that "many of the tadpoles that developed had deformities" and "some resulting tadpoles never metamorphosed." It also mentions that the effects could be reduced by adding supplemental thyroid hormone. Therefore, all of these options occurred.

When Investigators Exposed Embryos of African Clawed Frogs to Lake-Water