Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Which stage of a frog's life cycle can be compared to a plant seed growing into a new plant?
when frog eggs hatch into tadpoles
Tadpole (frog egg) is to frog as plant seed is to plant.