H and U are state functions but W and q are not state functions.

Which is not a state function of a thermodynamic system?

Work done is a path function (as it depends on the curve also called path) that is it is not a thermodynamic state function. So, the correct answer is option B that is work done.

Which of the following is not a state function a state function?

Work is not a state function as it depends upon the path followed.