a)

The question is asking for the speaker’s opinion.

Words that helped me decide: “Why does the athlete think”.

b) 

One option to eliminate: B

Answer B is wrong because in the extract below, the fact that an Olympic athlete travels a lot is presented as an advantage: “(...) and of course they have the opportunity to visit lots of interesting places (...)”. Thus, it cannot answer the question why being an athlete can be difficult.

c) The correct answer: C

Fragment w tekście: “They need to practise very frequently and they rarely get time off to spend with family and friends.” - Muszą ćwiczyć bardzo często i rzadko mają wolny czas na spędzanie go z rodziną i przyjaciółmi.