According to the information in the article, which of the following was essential for William Brown to be successful in his…

In studying northern timber rattlesnakes, he focused his attention on only one particular group.

He focused his attention exclusively on the reproductive behavior of northern timber rattlesnakes.

He discovered that northern timber rattlesnakes can live at least until age 50.

The New York State department of Environmental Conservation allowed him free access to the northern timber rattlesnake’s habitat in the Adirondack Mountains.

He was able to study one particular northern female timber rattlesnake from her birth to her death.