Which sentence contains correct parallel structure?

Keanon loves to biking, snowboard, and hiking.

Keanon loves to bike, snowboarding, and hike.

Keanon loves biking, snowboarding, and hiking.

Keanon loves biking, to snowboard, and to hike.

Keanon loves biking, snowboarding, and hiking.

Explanation:

This sentence contains correct parallel structure because it uses three identical grammatical forms (gerunds) as objects of the verb 'loves': biking, snowboarding, and hiking. That's parallelism.

The other sentences use different grammatical forms (gerunds and infinitives) as objects and, therefore, cannot be considered parallel in structure.