Answer:
(D) sensitive chemical tests and analytical instruments
Step-by-step explanation:
Toxicology is defined as a science that aims to study the harmful effects arising from chemicals in the body of living beings.
Early toxicologists had archaic chemical tests devoid of any kind of technology, and did not have analytical instruments, or did not have adequate analytical instruments so that they could properly analyze and test the effects of the chemicals. This lack of sensitive equipment and testing has made it difficult to research toxicology in ancient times, but over time, these elements have adapted and met the criteria needed to make toxicology the science we know today.