Rectilinear figure is formed by:
A. Plane
B. Points
C. Straight Lines
D. Can’t be determined

Hint- In geometry, a rectilinear figure can be defined as a plane figure or shape whose sides meet at right angles. These edges are formed by straight lines so as to form a polygon with all interior angles of ${90^0}.$

“Complete step-by-step answer:”
 A rectilinear figure can be defined as a plane figure or shape whose sides meet at right angles.

The interior angle at each vertex of the rectilinear is ${90^0}$ or ${270^0}$ . Here, for instance, a few irregular polygons that classify as rectilinear figures.
Hence, the rectilinear figure is formed by straight lines and the correct option is C.

Note- A plane figure whose boundaries are line segments is called a rectilinear figure.Students must not confuse a rectilinear figure with a polygon. A rectilinear figure may be closed or open. Also all the interior angles of a rectilinear figure are the same and equal to ${90^0}$ or ${270^0}$_.