A). However, the most successful way of combating smallpox before the discovery of vaccination was inoculation.
Explanation:
Central claim is elucidated as the key idea or argument that functions to unify the work in a single coherent thought.
The first option states the controlling idea of the given excerpt as it dominates the entire passage. It conveys the main idea of 'inoculation being one of the most successful ways to combat smallpox prior to the discovery of vaccination' to the reader which serves the key purpose of the author('to inform them about the treatment of smallpox before the discovery of vaccination'). It is the <u>central claim of the author that unifies the various ideas of the excerpt together in a unified thought</u>. Thus, <u>option A</u> is the correct answer.
Answer: ____________________________________________________________ The variable is QUANTITATIVE—since it is a measurable (numeric) value. ____________________________________________________________
