### Instruction: For real numbers $t,$ the point
\[(x,y) = (\cos^2 t, \sin^2 t)\]is plotted.  All the plotted points lie on what kind of curve?

(A) Line
(B) Circle
(C) Parabola
(D) Ellipse
(E) Hyperbola

Enter the letter of the correct option.### Response: So we have the point $(x,y) = (\cos^2 t, \sin^2 t)$.
We know that $\cos^2 t + \sin^2 t = 1$.
So then $y = 1 - x$.
That's the equation of a line.