“it is likely that ducks developed webbed feet because ducks need webbed feet for efficient swimming.” this attempt to explain the development of webbed feet in ducks most nearly matches the theory of evolution proposed by(1.1)

The correct answer is:  Jean Lamarck

The third Lamarck’s law says:

"The development of the organs, and their ability, are constantly a result of the use of those organs."

This means that his theory claims that organisms lose characteristics they do not require, or use, and develop characteristics that are useful for them (in this case the webbed feet of the duck).