Use the Ascaris worm to illustrate the complexity of the life cycle of a parasitic roundworm.
a. Ascaris worms have a simple, direct life cycle with no intermediate hosts.
b. The life cycle of the Ascaris worm involves multiple intermediate hosts before infecting the final host.
c. Ascaris worms have a complex life cycle involving transmission through vectors.
d. The Ascaris life cycle is still not fully understood due to its complexity.
