Answer: The model depicts the second law of motion.
Explanation :
According to Newton's second law of motion :
F = ma
where,
F is the externally applied force
m is the mass of an object
a is the acceleration produced
We can say that acceleration is inversely proportional to the mass of an object.
Higher the mass, less will be the acceleration.
So, the model illustrated by Cara and Sam represents Newton's second law of motion.
Hence the correct option is (B).