Question 1:
In the first question, the first highlighted sentence introduces the topic on xenotransplantation and tells a bit about the procedure. And in the second highlighted sentence, it tells about the concerns of animal welfare groups about genetically modifying animals for the sole purpose of organ harvesting.
Thus E is the answer i.e. first sentence introduces to the topic and the second sentence presents a criticism by animal welfare groups.

Question 2:
(2) The second option is true because of the second sentence of the passage.
(3) The third option is true because in the 4th sentence of passage it clearly tells that the record of success left much to be desired.
(4) The fourth option is true because the passage tells that organ transplantation from non human species is deeply woven in Greek mythology.
(5) The fifth option is true because the last line of passage tells so.
Thus option A is not correct and so is the correct answer as nowhere in the passage it talks about reducing the risks through xenotransplantation.