Both Darwin and Lamarck proposed mechanisms by which species might evolve. Although Darwin first published his ideas in the mid-1800s, most scientists continued to favor Lamarck's explanation until near the end of that century. What was the most likely cause of the eventual shift from Lamarck's hypothesis to that proposed by Darwin?

A new generation of scientists was more open to considering new ideas.
Lamarck's hypothesis did not take into consideration all that had been learned about genetics.
More evidence accumulated supporting Darwin's ideas than could be found to support Lamarck's.
It took several decades for Darwin's ideas to appear in textbooks and for scientists to learn about them.