A – Wrong
The text actually states that improved performance in extreme sports causes greater exposure to danger. The statement given in A actually strengthens the arguement.
B – Correct
If this statement is true, then people would not mind taking risks in order to escape the safety. Also, it would contradict the sentence “…do to counter the stress and pressure of work..”.
C – Wrong
This sentence actually strengthens the argument as it points out that designers encourage risk-taking. The last sentence “..equipment which are designed to make the sports safer…greater exposure to danger”.
D – Wrong
This statement just states the opposite of what the paragraph says. It does not ‘weaken’ it.