Question 1
Answer: D
The author didn't care. Look back to paragraph two and you'll see why. The author begins the part on why footballers suffer from cerebral issues by saying "perhaps" and is clearly engaging in speculative discussion without evidence or knowledge. It is true that, so far, C is looking promising. But not for long!
The author writes "Irrespective of this, it is empirically and scientifically proven to be the case", he dismisses his brief discussion as irrelevant speculation on a topic he clearly knows nothing about. It is correct to say he had some suggestions, it is wrong to say he believed he was correct. The final nail in the coffin is that "irrespective of this..." is very dismissive language, he is indifferent to the reasons, he just cares that the empirical evidence bolsters his view that boxing is extremely violent compared to other major sports.
Question 2
Answer: C
Firstly, what is meant by a 'moot point'? Well, this is a point that is irrelevant or not even worth discussing. Options A and B are easily removed because A is untrue (it is integral to the essay!) and B is not discussed in this context. C, D and E are more difficult, interestingly C is just a combination of D and E (both of which are correct). Thus we had a horrible "Final Three" situation, but it is relatively simple to see that C is a better version of D and E; thus, C is the most accurate response and therefore the best option to go for.
Question 3
Answer: D
B is obviously a real claim made by the author ("Interestingly, the same cannot be said for football") as is C ("outlaw... despite calls from major medical bodies") and E ("regulate... despite calls from major medical bodies").
The balancing act here is quite difficult. If you rely only on the reference to Muhammad Ali in the introduction then you may have incorrectly selected A. However, we can remove A as a result of Ali's mention in the 3rd paragraph where it says "Muhammad Ali would not have made it on to the death count statistics - despite the fact that he should have". Thus, the author makes a fairly clear claim that Ali died from boxing which, in order to support that conclusion, must be a claim that he got his Parkinson's from boxing.
Just for completeness, we should look at why D is not claimed. It is summed up in this sentence that "boxing was currently socially acceptable and that the infliction was not intended or the object of the sport". D is too inaccurate to be true, thus it is our answer.