Please correct the wrong question.
To the editor of practice test section and the respective author of the following question,Today while I am gothroughing through some of the questions, I found one question that ' Isotherm is for temperature and Isobar is for ________'.
As far as my knowledge, the answer to this question is Pressure but the author has mentioned that Altitude. So, please have a look at that question and please re-edit after searching about it.
My explanation is that isotherm means at constant temperature and Isobar means at constant pressure.