Will give ! find the coordinates of the orthocenter of abc. a(0,0), b(5,0), c(5,3)

If you sketch the triangle you will see it is a right triangle with B being the vertex for the right angle. 
the orthocenter is the intercept of the three altitudes. for a right triangle, the orthocenter is the vertex where the right angle is.
so the answer for this question is (5,0)

i believe your answer is b.

good luck!

cutie~