The diagram shows three vectors.

which best describes a relationship among the vectors?

vectors p and py are components of vector px.
vectors px and py are components of vector p.

Any vector which is made in x-y plane will have some angle with the x axis

in that case we can say that

also for Y direction we can say

so here the two components of vector is given by Px and Py

so we can say that

so correct answer would be

Vectors Px and Py are components of vector P.

the independent variable, or the one that is intentionally manipulated is the speed.