Would you please tell me if we can use the superlative even though there are two choices?
1. Which do you think the correct answer is, 'a' or 'b'? / I think both are correct, but that 'a' is better/best.
2. Although both of them have tried, she has the highest grade.
3. The book is the most interesting of the two.
4. This book is most interesting than that.
Thank you very much.