Question

read the paragraph, then choose the word that best completes the sentence. scientists have discovered that people carry a staggering variety of bacteria on their hands. they found a total of 4,742 different species. individual test subjects averaged 150 different types, with women averaging more types of bacteria than men. scientists are not sure why but have offered several possible explanations. the difference may have something to do with acid on the skin. a mans skin generally has more acid than a womans skin does, and bacteria do not thrive as well in more acidic environments. another cause could be the differences in sweat and oil produced. makeup use could also make a difference, as could skin thickness. scientists have created many ______. a hypotheses b patents c routines d formulas

Explanation:

The text mentions that scientists are not sure why women have more types of bacteria on their hands than men but have offered several possible explanations. These possible explanations are hypotheses. There is no mention of patents, routines, or formulas in the context.

Answer:

A. hypotheses