The "rattling off my plans" one
The detective continued to search for the missing girl.
infinitive: to search.
infinitive phrase: to search for the missing girl.
Just when he started to doubt his plan, he found the scared young girl behind the door to the cabin.
infinitive: to doubt.
infinitive phrase: to doubt his plan.
Answer: Genetic Engineering
Explanation:
BIG OOOOOOOOOOOOOOOOOOOOOOOOOOOF