I need to know if the following is considered a sentence or a fragment. "Whose work on the chalkboard"

Answer 1

It is a fragment. Since there is no verb in the first part, it is a phrase that would lead to the next part of the sentance.

Whose work on the chalkboard led to solving a problem that had not been solved before.

Answer 2

It is neither a sentence nor a fragment because it lacks a verb.
Whose work Is on the chalkboard?
..whose work is on the board...

Answer 3

This is not a sentence because it does not contain a verb. to make it a sentence you could use the word "is"
Whose work is on the chalkboard?
Hope this helps.