Jason wanted to be sure that his classmates knew the sources he was using for his speech so he used in his speech when he referenced an original source.

a. oral footnotes
b. visual aids
c. note cards
d. statistics

A. oral footnotes

Explanation:

Oral footnotes -

In a speech , some kind of internal references which lead to the main source of the subject or topic , is referred to as the oral footnotes.  

Oral footnotes need to be included in the speech , when the information is taken from any external source.

But information need not be plagiarized .

Hence, from the given information of the question,  

The correct option is A. oral footnotes .

answer: corporations and the wealthy cannot donate an excessive amount. (c)