I think the answer is A
hope this helps
When added to the word detect, the suffix which means "a person who" is -ive.
"A person who" means that you need to create a noun which refers to a person by adding that suffix. If you add -ive to detect, you will get the noun detective, which is obviously a person.
The word detectary doesn't exist, and the word detection doesn't refer to a person, but rather the act of detecting.
What is the story, could you please give more details and I will see what I can do.
Answer:
job opportunities might have pulled the Solutreans into North America.
