Read the following excerpt carefully before choosing your answer. This passage is from then-Senator Barack Obama's November 2007 Speech on the "American Dream."

"The steel plant had closed. Jobs were disappearing. In a forgotten corner of America, the American dream was slipping away. And I knew dreams are worth fighting for."

The purpose of including this line at the beginning of his speech is to

build an emotion of hope by creating an image of equality
engage the audience by establishing authority and credibility
add reliability to his argument by quoting experts
establish the need for hope by using concrete examples