Please help!! Will mark brainlyest.

C
Line symmetry is when a shape can be folded over an imaginary axis and have both sides be a mirror of the other. This axis is called the line of symmetry.
Letter C
In this case, if you draw a horizontal line across the middle of the letter "C" and fold the letter, each half would be the same. The top half of "C" mirrors the lower half.
Other Examples
The lowercase letter "l" also has 2 lines of symmetry. You can draw both a horizontal and vertical line across the letter and each side will mirror the other.