Answrs: Part a) "Facts from a documentary.." This is talking about the benefits of artificial organs instead of donated ones.
Part b) "There are several ..." Because it is a sentence that is likely to precede facts. The others are opinions about how something 'SHOULD' be, and aren't presenting facts or claiming something.The first one 3ven says "I think..." which is clearly an opinion.
I found this for your question
I bought my brother some gift-wrap for Christmas. I took it to the gift-wrap department and told them to wrap it, but in a different print so that he would know when to stop unwrapping.
answer: We can't just write a whole essay i-
