Read the excerpt from "edward jenner and the history of smallpox and vaccination.”

smallpox was introduced to europe sometime between the fifth and seventh centuries and was frequently epidemic during the middle ages. the disease greatly affected the development of western civilization. the first stages of the decline of the roman empire (ad 108) coincided with a large-scale epidemic: the plague of antonine, which accounted for the deaths of almost 7 million people. the arab expansion, the crusades, and the discovery of the west indies all contributed to the spread of the disease.

the author most supports his argument that smallpox devastated mankind over the centuries by providing

a historical timeline.
an alternative claim.
details of a historical incident.
interesting, partially related facts.\

answer is a

A historical timeline.

Explanation:

In any form of narration, the writer's inclusion or use of the historical timeline or chronological presentation of facts and details give a far more solid proof for the points made. This allows the credibility of the given information to the readers, and in turn provides credibility to the author/ writer too.

In the given excerpt from the text "Edward Jenner and the History of Smallpox and Vaccination" by Stefan Riedel, the writer narrates how the issue of smallpox came from "Europe sometime between the fifth and seventh centuries". Then, it passes through the Middle ages till "the Arab expansion, the Crusades, and the discovery of the West Indies" which "all contributed to the spread of the disease". Thus, he uses the historical timeline of how smallpox came about to support or lay claim to his argument of how this disease brought devastating effects to mankind over the centuries.

a

Explanation: