Which part of speech is the underlined word?

that was such a good movie.

a.
preposition

b.
verb

c.
adjective

d.
noun
was is underlined

answer: c

explanation:

a long work of fiction-novels contain such elements as characters,plot,conflict,and setting. the writer of a novel, or novelist, develops theses elements. in addition to his main plot, a novel may contain one or more subplot, or independent, relate stories. a novel may also have several themes.

i read that book for k12 but i don’t remember sorry.