'this year' is the adverb of time
The answer is A, true.
There is a quizlet (search the same question in go0-gle) that mentions this question, I’d suggest to give it a look if you have any problems answering questions.
I feel like the answer is A.
Because back then they believe that if they didn't see it then it is not there or created for example when the french believe that the earth is flat but we know now that it is round.
