Correct option is 4th .
Object increased its velocity for 1 sec , then moved with constant velocity for 4 second , decreased velocity for 1 sec, moved with constant velocity for 2 sec.
According to given velocity -time graph , slope of graph increasing for first second . It indicates increase in velocity . Then graph remains parallel to time axis for 4 sec. This indicates velocity is not changing with passing of time i.e. velocity is constant . Next slope of graph decreasing for 1 sec indicating decrease in velocity . Finally graph remains parallel to time axis for 2 sec indicating constant velocity .