Shouldn't the word "in" be in quotes?

[Teacher]

English Language Tests, Intermediate level

ESL/EFL Test #99 "Student Teacher Dialogue (2)", question 4

Student: If I had to choose one, I would ......... in.

(a) turn
(b) pick
(c) touch
(d) pluck

English Language Tests, Intermediate level

ESL/EFL Test #99 "Student Teacher Dialogue (2)", answer 4

Student: If I had to choose one, I would pick in.

Correct answer: (b) pick
_________________________

Shouldn't the word 'in' be in quotes? This is very confusing.

English Teacher

[Pamela]

You may if you pick the preposition "in".