Which of These Was NOT an Important Factor in Setting

Multiple Choice

Which of these was NOT an important factor in setting the stage for Columbus's exploration of the New World?

A) European demand had increased for more and cheaper products from Asia.
B) Africa was established as a source of slave labor.
C) The Portuguese had demonstrated the feasibility of long-range ocean navigation.
D) The Renaissance nurtured a spirit of optimism and adventure.
E) There was explosive population growth in Europe.