Which part of speech is the underlined word? within five minutes, the firefighters had the fire under control.
a. interjection
b. adverb
c. preposition
d. conjunction

Within five minutes, the firefighters had the fire under control.
Let's try to assign each word what it is since the underline is not present.

within - (C) preposition
five minutes - (B) adverb
the firefighters - noun
had - verb
the fire - noun
under - (C) preposition
control - noun

But she forgot her paw patrol lunchbox so she had to eat the disgusting school lunch, it was the worst experience of her life.