D - The narrator says he will die the following day.
In the first paragraph of Edgar Allan Poe's "The Black Cat", the narrator says, "But to-morrow I die, and to-day I would unburthen my soul," meaning that he will die the following day.
Then he goes into his childhood and marriage.
a. three major supporting details.
There are three supporting details for the main idea on the theories to explain why people yawn. Each of the supporting details contains a key word or phrase to indicate that they indeed are a main supporting detail. These key words and phrases are "One explanation is...", "A second theory...", and "Yet another explanation...". These all show the supporting detail is contained in the sentence. The last sentences just build and connect to information that has already been introduced.
B. I'm grateful to have the opportunity to speak to you today.
