I am not 100% sure but I think it is c. Your best bet is to look it up on google that’s what I tried but my google is bugged out.
The coordinating conjunctions among these are and and so.
However and therefore are not - they are subordinating.
Rukmani's struggle to feed her family during the drought is an example of an external conflict!
air, heir aisle, isle
some sum son, sun
stair, stare stationary, stationery
steal, steel suite, sweet
tail, tale