Scientists Began Studying Leeches

Multiple Choice

Scientists began studying leeches

A) over 100 years ago, due to their widespread use in medicine.
B) in the 1960s with the advent of modern neuroscience.
C) in the early 2000s, when they were discovered for transgenic use.
D) in the early 2000s, when they were used to trace embryonic cells.
E) only recently, when their genome was sequenced.