When asked this question, I would stay away from saying that you have a least favorite grade because as a first year teacher, you may not have the luxury of choosing which grade or subject you want to teach. You can say what grades and subjects you have the most experience in, but be open to trying new grades and subjects. In order to become a well-rounded teacher, you must seek experience in other areas. Getting out of your comfort zone will be beneficial in the future.

For first year teachers simply state that you don't have a least favorite grade or subject as you don't have much experience. Instead talk about subjects that you believe were a little harder for you to study and learn about. For experienced teachers try and name a subject or grade that you truly struggled in the most. If you struggled in Kindergarten simply state it and explain why. State you prefer older grades because the material was more advanced and easier for you to teach.

I would explain that I do not have a least favorite subject as of right now for I don't have the experience to make that decision. I'm open to teaching anything, especially as a first year teacher.

I would explain an area that I have had difficulties in (either learning or teaching) and how I have overcome those difficulties. I wouldn't say that any subject is my least favorite, just that there are subjects that are more challenging.

I posted on my answer to what you be my favorite grade to teach, which is the younger grades. I feel like the younger students are more excited and eager to learn. When the older students learn something in class, some of them have already learned it, and they do not have the same curiosity and wonder about why? or how? like the younger students do. Even if the older student did not understand the material, they will usually not even ask. It will be clear to see on their assessment though.