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 | ríða | reið | riðu | riðinn | to ride |
| 2a | lúka | lauk | luku | lokinn | to finish |
| 2b | frjósa | fraus | frusu | frosinn | to freeze |
| 3a | binda | batt | bundu | bundinn | to bind |
| 3b | verða | varð | urðu | orðinn | to become |
| 4 | bera | bar | báru | borinn | to bear |
| 5 | lesa | las | lásu | lesinn | to gather, to read |
| 6 | ala | ól | ólu | alinn | to grow, to produce |
| 7a | heita | hét | hétu | heitinn | to be called |
| 7b | hlaupa | hljóp | hljópu | hlaupinn | to leap |
| 7c | halda | helt | heldu | haldinn | to hold |
| 7d | ráða | réð | réðu | ráðinn | to advise |
Question:
What class is the verb wich its part 4 is frosinn
Answer:
2b