If 'so' in line 2 of the stim changes to 'for example', then will A be the right answer?

I got this question, but it took me 2:25 (+1:13). My problem was mostly to understand what they actually mean those answer choices from A to E. Will this be eventually better with practice? Any advice please?

If A was "in spite of the difficulties encountered, at one time or another people have tried to domesticate each wild large mammal species (adding)* that seemed worth domesticating <--added" Then would it become another correct answer choice?