Cognitive:
This is because teens tend to excrete more hormones when they are in their adolescent ages causing them to act in a riskier behavior.
Emotions:
Because of their feeling that they want to have freedom.
Physical:
Their hormones are affecting their actions.
Answer:
The force of friction acting on block B is approximately 26.7N. Note: this result does not match any value from your multiple choice list. Please see comment at the end of this answer.
Explanation:
The acting force F=75N pushes block A into acceleration to the left. Through a kinetic friction force, block B also accelerates to the left, however, the maximum of the friction force (which is unknown) makes block B accelerate by 0.5 m/s^2 slower than the block A, hence appearing it to accelerate with 0.5 m/s^2 to the right relative to the block A.
To solve this problem, start with setting up the net force equations for both block A and B:

where forces acting to the left are positive and those acting to the right are negative. The friction force F_fr in the first equation is due to A acting on B and in the second equation due to B acting on A. They are opposite in direction but have the same magnitude (Newton's third law). We also know that B accelerates 0.5 slower than A:

Now we can solve the system of 3 equations for a_A, a_B and finally for F_fr:

The force of friction acting on block B is approximately 26.7N.
This answer has been verified by multiple people and is correct for the provided values in your question. I recommend double-checking the text of your question for any typos and letting us know in the comments section.
The answer is no moons<span> at all. That's right, </span>Venus<span> (and the planet Mercury) are the only two planets that don't </span>have<span>a single natural </span>moon<span> orbiting them. Figuring out why is one question keeping astronomers busy as they study the Solar System.</span>
Instead of asking this question go and study
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