Answer
(a) True.
(b) False.
(c) True.
(d) True.
Work Step by Step
(a) True. Translating (moving) a vector does not change it.
(b) False. A unit vector has a particular length (1 unit).
(c) True. Moving a vector to the origin will keep it parallel to the original vector.
(d) True. Changing the length of the vector will not change its slope/direction.