The graph below represents the $y-$component of the velocity of an object as a function of time. Which of the

following could be a reasonable description of its motion?

Select one:

a$.$ The object accelerates upward at a constant rate and then accelerates downward until it hits the ground at $t$

$=6s.$

b$.$ The object accelerates upward at a constant rate and then accelerates downward until it reaches it highest

point at $t=6s.$

C$.$ The object accelerates upward at a non$-$constant rate and then accelerates downward until it hits the ground

at $t=6s.$

d$.$ The object accelerates upward at a non$-$constant rate and then accelerates downward until it reaches it

highest point at $t=6s.$

e$.$ None of the choices