Which is defined using the undefined terms point and line?
a)angle
b)circle
c)parallel lines
d)ray

A ray is defined using undefined terms point and line. Think of it this way, a ray has a point and line, but how do you know what someone is talking about if they just use the term "point and line"? Well, in geometry a circle could consist a point and line for finding the diameter, but that is not specific enough. So, next we go to the next option angle, well, yes, a angle could consist a point and a line, but still the term "point and line" does not 100% fit the term. Third, we have parallel lines. Parallel lines do consist a line and sometimes a point to show distance in geometry, but still... not specific enough. Finally , we have the option ray, now, rays do consist of a point and a line, and the term "point and line" fits perfectly with the optian ray.