The correct answer is: a few.
The word “few” is used to describe a small number of things. In this case, the speaker is saying that they have a small number of options left to solve the question. This suggests that they are still hopeful that they will be able to solve the question, even though they have not yet found the answer.
The word “little” is also used to describe a small number of things. However, it is often used to describe a small amount of something that is not very important. In this case, the speaker is not saying that the number of options they have left is not important. They are simply saying that it is a small number.
The words “a few” and “little” can both be used to describe a small number of things. However, they have different connotations. The word “few” suggests that the number of things is small but still significant. The word “little” suggests that the number of things is small and not very important.
In this case, the speaker is using the word “few” to describe the number of options they have left to solve the question. This suggests that they are still hopeful that they will be able to solve the question, even though they have not yet found the answer.