Anew drug is discovered for the treatment of thyroid cancer. which is logical next step of the scientific method after the discovery has been successfully tested
a. testing the drug on people
b. keeping the information private
c. testing the drug on animals
d. sharing the data with other scientists

Ideally, the data would be shared with other scientists in the form of a research paper submitted to a respected scientific journal in a relevant field. After the paper would be published, more scientists should be able to replicate these results and if their results point in the same direction - that indeed a drug that treats thyroid cancer has been found, then the next step would be to gain ethical approval and test the drug on animals. 

So in summary, it would be best to do D first and C second.