An elephant has a long, powerful trunk. According to the ideas of Lamarck, how did the trait of long, powerful trunks develop in elephants ?
A Suddenly, after one elephant was born with a long, powerful trunk
B. Suddenly, after one elephant developed a long, powerful trunk as it grew.
C. Gradually, as elephants began mating with animals of other species that had long trunks.
D. Gradually, as generations of elephants continued to selectively use and develop their trunks.