Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Class | Part 1 | Part 2 | Part 3 | Part 4 | Verb meaning |
| --- | --- | --- | --- | --- | --- |
| 1 | rijden | reed | reden | gereden | to drive, to ride |
| 2a | vriezen | vroor | vroren | gevroren | to freeze |
| 2b | sluiten | sloot | sloten | gesloten | to close |
| 3a | binden | bond | bonden | gebonden | to bind, to tie |
| 3b | bergen | borg | borgen | geborgen | to protect, to store away |
| 4 | stelen | stal | stalen | gestolen | to steal |
| 5 | geven | gaf | gaven | gegeven | to give |
| 6 | graven | groef | groeven | gegraven | to dig |
| 7b | lopen | liep | liepen | gelopen | to walk, to run |
| 7c | vallen | viel | vielen | gevallen | to fall |
| 7d | slapen | sliep | sliepen | geslapen | to sleep |
Question:
What's part 1 of the verb whose part 4 is gevroren?
Answer:
vriezen