Statement III is correct context switching of kernel level threas are higher then user level thread as user level thread are transparent and have less context compared to kerel level thread
Statement II. is also true here page fault is related to when a process blck that is when any of the user level thread get block complete process will get in block state as user level threads are dependent on each other but this is not true in kernel level thread, kernel level thread will still do work correctly
Statement I is true itself.
All are true