The right answer would be "A". Here is why:
It is not "B" because experts' would be if you were talking to someone and you were saying they had or did something.
For example: The experts' smart.
But that's not what this sentence is about.
It is not "C" because expert's is like if you were saying "They appreciate getting an expert is advice."
So the correct answer is "A".
I hoped this/ I helped.
Please make sure to give me a Brainliest for answering your question. (Not saying you need to. It's just that I need one more to get to my next level.
:D