1. *The* players will come back *at* 5 *in* *the* afternoon.
2. Naren *arrives* home by this time tomorrow.
3. This is the most *extravagant* stone in the store.
I put ‘the’ ‘at’ ‘in’ and ‘the’ for the first sentence as it makes it grammatically correct and make sense.
I put ‘arrives’ for the second one because it makes sense in the sentence as well and with the hint (reach) you can also tell that arrives will be the answer.
I put ‘extravagant’ for a positive form of ‘costliest’ because costliest means very expensive and was described in a negative form but extravagant means showing no lack in money by spending it on resources which favours the stone.
Hope this helps!