Read (or reread) these two paragraphs from a science course, looking for differences in how the ideas are organized and presented. Light
Light passes through some materials without scattering. We call objects of this kind transparent. Clear glass and clear plastic wrap are two transparent objects. Other objects, such as wax paper or frosted glass, let some light through but scatter or block the rest. These objects are translucent. Then there are opaque objects, which do not let any light through. Opaque objects block all light. Instead, they produce shadows on a surface when an object prevents light from reaching that surface. You are an opaque object. So is a wooden door, a refrigerator, or a moose.

Sound
Sound travels in waves that are produced when something vibrates. Sound waves are invisible—we cannot see the movement of sound through the air with our eyes. Unlike light, sound needs a medium, something to travel through. Sounds can move through solids like walls or clothing, liquids such as water, or gases such as air. Walls, water, and air are all examples of different media through which sound travels.

Which answer does a good job of contrasting the two paragraphs?

A. Both paragraphs use lots of familiar images to help readers imagine how energy flows through things.

B. Both paragraphs focus on substances that an energy form might travel through.

C. One paragraph introduces and defines basic terms while the other sticks with more basic information.

D. One paragraph is about how light travels, and the other is about how sound travels.