What part of speech is the underlined word in the sentence?

This is my favorite book about space travel.

A.
adjective

B.
noun

C.
adverb

D.
pronoun

The underlined word is This

Question

What part of speech is the underlined word in the sentence? 

This is my favorite book about space travel.
  
 
 

 
 

  

  A. 
  adjective   
   

 
 

  

  B. 
  noun   
   

 
 

  

  C. 
  adverb   
   

 
 

  

  D. 
  pronoun  
 

The underlined word is This

anonymous · Answer

@Slapshot77

anonymous_user · Answer

I believe it's an adverb

anonymous · Answer

I don't think so because my book shows all the adverbs and the word this is  not one. Also, school gave me the book so adverb must be wrong. But that is all I know..

anonymous · Answer

Its a pronoun because it's taking the place of a noun. "This" could have been the book name