What type of pronoun is the word in bold?

That is definitely not the course of action I would take

A. relative

B. demonstrative

C. indefinite

D. interrogative

Relative pronouns - introduce a dependent clause

who, whom, which, that

demonstrative - demonstrate

this, that, these, those

indefinite - used for non specific items and people

anyone, someone, all, both, few, each ...

interrogative - begin questions

who, which, what, where, how

In this case I think it is demonstrative