Select the option that is related to the third word in the same way as the second word is related to the first word. (The words must be considered as meaningful English words and must not be related to each other based on the number of letters / number of consonants / vowels in the word.)

Trembling : Fear :: Sigh : ?

Relief

Trembling : Fear :: Sigh : ?

The logic followed here is :.

Trembling : Fear

Trembling means shaking slightly  in a way that you cannot control, for example anger or fear

Similarly

Sigh : ?

Sigh means to take a long deep breath of relief