Suppose that the electron is replaced by a proton with the same initial speed v0. Would the proton hit one of the plates

Letter a, because when there are unlike charges they will always attract to each other.

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero. 

Answer it orbits high above earth to gain clearer images of light, it magnifies images relative to the human eye, it records most of the universe as it was in the past, not as it is now;

Ansa new gas is observed in the form of bubbles;