It Was Difficult for the Research Teams Led by Roger

Multiple Choice

It was difficult for the research teams led by Roger Guillemin and Andrew Schally to discover thyrotropin-releasing hormone and gonadotropin-releasing hormone because

A) they had no access to a supplier of hypothalamic tissue.
B) the amount produced in a single individual is miniscule.
C) they were unable to characterize the hormones once isolated.
D) they were the first to hypothesize that such hormones existed.
E) there was no assay for testing the substance they had isolated.