Parallel and perpendicular lines.

The answer is the last choice  

Explanation:

Well i think this because we have no info about line L so we cant make assumptions but we do know that M and P are perpendicular this means both lines are straight also p and n are parallel so also n is a straight line meaning that m and n are perpendicular making a perfect 90 degree angle    

b.

developed countries have tended to improve the environment, while developing countries have tended to damage it.

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.