A Census Bureau （人口调查局) survey released Thursday shows a college graduate can expect

A Census Bureau (人口调查局) survey released Thursday shows a college graduate can expect to earn $ 2. 1 million working full-time between 25 and 64, which demographers (人口学家) call a typical work-life period. A master' s degree-holder is projected to earn 2.5 million, while someone with a professional degree, such as a doctor or lawyer, could make even more--$ 4.4 million. In contrast, a high school graduate can expect to make $ 1.2 million during the working years, according to the bureau report that tracked the influence of education on lifetime earnings.

Not all students look at college as an investment, "but I am sure parents do," said Jacque line King, policy analyst with the American Education Council, a higher education advocacy (拥护) group. "The college is to convince those high school students on the margins that it is really worth their time to go to college." Kevin Malecek, a graduate student in American poli tics at American University in Washington said most of his classmates find higher education to be worth the time and financial promise. "They go to every single class, and they are trying to get the most out of their own dollar," he said. The survey was conducted between March 1998 and March 2000. All estimates are based on 1999 salaries and probably will increase as salaries rise over time, Census Bureau analyst Jennifer Day said. The estimates do not account for inflation (物价上涨) or for differences in the earning potential of various fields of study. For example, people with computer science degrees tend to earn more than those with social work degrees.

The phrase "students on the margins" in Line 3 of Paragraph 2 most probably refers to ______.

A．students Who actually regard higher education as an investment

B．students who can't afford the money to go to college or university

C．students who can't go to college because they have failed in the college entrance examination

D．students who don' t know whether higher education can have great influence on their earnings