Why is bahkan before mereka?
After what I have seen throughout this course, in subordinate clauses the adverb has to go at the very beginning.
This answer should also be accepted ? "mereka orang-orang miskin, mereka bahkan tidak punya air" and the same for "mereka orang miskin, mereka tidak bahkan punya air" - both marked wrong
Your first alternative is correct, though reduplicating "orang" is unnecessary because the plurality is already indicated in the word "mereka".
Your second alternative is incorrect. The word "bahkan" can't be placed after "tidak".
They must've change it... "... mereka bahkan tidak punya air," is now accepted.
Why is bahkan before mereka cannot work this out?