Which of the following sentences contains an infinitive?

After a long day at school, there was nothing Chantal loved more than a long swim in the pool.
Chantal loved to swim in the pool for fun, even when it wasn't a practice day.
Chantal was quite accomplished at swimming; she had placed first in every competition since age eight.
Since the age of eight, Chantal had won every swimming competition she had entered.

Chantal loved to swim in the pool for fun, even when it wasn't a practice day.

The sentence that contains an infinitive is: "Chantal loved to swim in the pool for fun, even when it wasn't a practice day."