Judicious means having, showing, or done with good judgement or sense.
Hence option C is the correct answer because “sensible” means done or chosen with use of wisdom likely to benefit, hence it is correct.
Option A is incorrect because “nervous” means to be easily agitated or alarmed, which is not related to being sensible.
Option B is incorrect because “helpful” means to be of a genuinely helping and kind nature which is irrelevant here.
Option D is incorrect because “cautious” means to be alert which is incorrect here.