If you're talking about the boundary line of the answer sheet, that won't do. The boundary line on the answer sheet is clearly marked, which exceeds the answer area and cannot be scanned. The excess part will not be scored.

If it is for the convenience of physics or mathematics, it is ok to divide the answer area in a question, and even many teachers will ask students to draw a dividing line for the convenience of answering questions.

Generally speaking, multiple-choice math problems are graded by computer, and the big questions behind are presented on the computer, and then graded manually. You can draw auxiliary lines on the graphics on the answer sheet to show the practice of auxiliary lines. If the answer is helpful to you, I hope to adopt it. Thank you.