What observations led to the proposal of Dark Matter? Typically in science, you do not come up with an extension of your theory or propose a new hypothesis unless new data contradicts existing ideas.

Explanation:

Two teams of astronomers observed in 1988 that the universe was accelerating in expansion. They proposed that a phenomenon known as dark energy could be responsible for the development. They came to this conclusion by measuring lights emanating from exploding stars called type 1A supernovae.

this doesn't support enough information to answer the question.

answer; (true);