When the acceleration of a mass on a spring is zero, the velocity is at a

When a mass is connected to a spring then it will perform to and fro motion

Its velocity and acceleration is given by the equations

so here from above equations we can say that if object moves away from its mean position then its velocity will decrease and as it reached to the extreme end its velocity will become zero

while at mean position the velocity will be maximum

Similarly for acceleration we can see that its magnitude will be maximum at extreme position and it will be minimum as object will reach to mean position

So at extreme position velocity will be zero while the acceleration is maximum

i believe it is b. what was the cause of the big bang

hope this !

could you add the photo?

explanation: