At school, he learns 10 subjects such as math, science, social studies, computers, ethics, etc. He is in math class now. He has a cell phone. He is sitting at the back. One of his friends calls him and asked "Which class are you in?" What is the answer to the question.

Question

1. I'm in math class.
2. I'm in Class 1-2.
3. I'm a student in Class 1-2.

Answer 1

#1 is best. If the class is well-known as "class 1-2" instead of "math class", that is fine, too.
To say one is a student in the class does not tell where the student is at the moment, but merely that he/she is taking the class when it meets (which may be at any prescribed time, not at this present time).

Answer 2

Identify the function of the phrase contained in the following sentence.

Her main concern was wearing a diamond necklace.