Answer:
B). 3.4 s
Explanation:
As we can see the graph is given between velocity and time
so here we can see that the velocity is changing here with time and initially for some time it moves with constant speed
Then it's speed decreases to next few second and then speed increases to its maximum value
The time after which velocity comes to its maximum value will reach after t = 3 s
so out of the all given options most correct option will be

A switch
What are the answers choices
The era that dinosaurs came was in the Mesozoic Era!
When Object is at zero height, and there is no potential energy possess by the object then it exerts Greatest Kinetic energy in it's whole Journey
Hope this helps!