Hi Ammu,
I would refrain from any answers referring to your chosen research methods as it indicates you are not certain about your choices and decisions made along the project. You've not given enough context but if you're in natural sciences nothing about failed results - this is a question to reflect on any lessons you've learned as a result of your choices.
A good way to connect this answer is to relate it to comments for future study that are usually found in the conclusion of your thesis.
Good luck,
K