Correct Answer: as dead as a doornail

Solution : The correct answer is the second option.

This idiom means that something is completely lifeless or no longer functional, which accurately conveys the idea that the career is obsolete and no longer viable.

The meanings of the other options are as follows:

Moving like a worm: This phrase describes someone moving slowly in a wiggling, struggling manner, like a worm.

Dead even: This phrase means that two competitors or options are exactly tied, with no advantage to either side.

Hanging by a thread: This idiom suggests a situation that is in a precarious or unstable state, where a minor event or issue could lead to a catastrophic outcome.

So, the sentence would be: "Your career is now as dead as a doornail. "