Fill in the blank with the most appropriate option.
Renu is a _______. You can lead her by the nose.
The idiom “lead someone by the nose” means exerting complete control over someone. It can be possible only when a person is not very intelligent and can easily be fooled. “Simpleton” is the right word to describe such a person. Hence, Option D is correct. The rest of the options do not express this condition, hence incorrect.