Which best describes the speed and velocity of the graph? a) both speed and velocity are changing. b) the speed and velocity remain constant. c) the speed is constant and velocity is changing. d) the velocity cannot be determined from the graph.

This is tricky, but the correct answer is A.

Choice-D is also true.  We can't COMPLETELY determine velocity
from the graph, because an essential part of velocity is the DIRECTION
of motion, and the graph doesn't tell us anything about the direction.

But even though we can't COMPLETELY determine velocity from
the graph, we DO know that velocity is changing, because the speed
is definitely changing, and speed is the other big part of velocity.

The graph shows clearly that speed is changing.  That right there
tells us that velocity is also changing, and we can pick choice-A.

Well the magnitude of its acceleration related to that car starts with the oil change like when you have to change the oil in your car you have to make sure that your precious car is starting really propley and very well