How does a grid made of lines help in drawing?

In keeping proportion and placement correct

A grid is a set of crossing horizontal and vertical lines that divides the drawing area into smaller sections. It works like a guide, helping the artist judge where each part of an object should be placed. It is especially useful when copying a picture, enlarging it, or keeping several parts in correct proportion. The lines are guides, not the final picture, so they can be removed or hidden after the drawing is complete.

Option A is correct because a grid helps compare the size and position of an object with the corresponding sections of a reference image. For example, an artist can notice that an eye begins in a particular square and has a certain width. Options B, C, and D describe effects unrelated to a grid: it does not make a drawing invisible, change the smell of paper, or erase colours. Therefore, the grid is mainly a tool for accurate proportion and placement.

This is a Class 9 Art Education question. Chapter: Elements of Art. Topic: Line.