Verified Answer :

Sansacrasial

¿Cuál es un adverbio?
Well, an adverb is a word or phrase that modifies an adjective, verb, or another adverb. Adverb's consists of things such as place, time, manner, cause, etc. So, the correct answer should be C) restaurante, since it is a PLACE. 

Good luck with your studies, I hope this helps!

Históricamente is an adverb. It means 'historically.' There are lots of adverbs in Spanish that end in '-mente' that correspond to English adverbs that end in '-ly'.