Most frog species have a distinct tadpole life stage However

Most frog species have a distinct tadpole life stage. However, microhylids of Australia and new Guinea do not have a tadpole stage, but tadpole features appear and disappear during development in the eggs. This shows that

Solution

Third option is the answer.

It evolved from an ancestor with tadpole stage.

The microhylids of New Guinea and Australia completely bypass the tadpole stage, with direct development from egg to frog. The arboreal species can therefore lay the eggs within the trees, and never need venture to the ground. Where species do have tadpoles, these almost always lack the teeth or horny beaks typical of the tadpoles of other families.