[AP 1989] Which of the following had the LEAST effect on European thought in the first half of the 20th century?

Question

a. the uncertain and complex universe of Einstein's and Heisenberg's physics

b. the undermining of the optimistic belief in human rationality by Freudian psychology

c. the utopian literature of Sir Thomas More and Roger Bacon

d. logical empiricism's limitation of the scope of philosophical inquiry to the scientifically and mathematically verifiable

e. the Darwinist idea of human behavior as determined by evolutionary forces