Answer:
the definition of migration is option B
Density is mass of object per unit volume
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Hello!</h2>
The answer is:
b. 
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Why?</h2>
The centripetal acceleration or radial acceleration is present when an object is moving to describe a circular path. The centripetal acceleration is always perpendicular to the direction of the velocity and going inwards and towards the center.
The centripetal acceleration can be calculated using the following equation:

From the statement we know that:

So, calculating we have:

So, the correct answer is:
b. 
Have a nice day!
Answer: The motion is accelerated.
Step-by-step explanation: Given that the horse is walking along a straight line.
The horse travels 3 m in first second, so its speed is 3m/s.
In the next second, the horse travels 4 m, so its speed is 4 m/s.
In the third second, the horse travels 5 m, so its speed is 5 m/s.
Since the speed of the horse is increasing per second i.e., the speed in not constant, so the motion of the horse is accelerated.