Question

how does popcorn pop?

1. its movie night. you reach for your favorite snack. but did you ever wonder how those tiny, hard kernels pop into fluffy, salty popcorn? and why is popcorn a corn if it looks nothing like the yellow stalks on stalks?
2. corn comes in all different types, like dent corn, flint corn, pod corn, flour corn and sweet corn. sweet corn is the corn that comes off a stalk and the type familiar to most americans. popcorns strain is called zea mays everta and is a type of flint corn. over the years, zea mays everta corn has grown specifically to pop even better.
3. like sweet corn, popcorn kernels are seeds. and like most seeds, the kernels hull contains an embryo (baby plant) and a starchy coating called the hull to keep the embryo safe. the rest of the kernel is filled with starchy endosperm that has about 14 - 20% moisture and proteins. the endosperm provides food for the embryo. popcorn kernels are harder than sweet corn, which is one reason a popcorn kernel can pop. the other reasons are the starch

how does the inclusion of the diagram help the reader understand the article?
a it demonstrates how popcorn kernels are grown and harvested.
b it explains the nutritional value of popcorn and how butter affects its texture.
c it illustrates how heat and pressure cause popcorn kernels to pop.
d it shows the different types of corn and helps the reader distinguish between popcorn and sweet corn.

Explanation:

The article is about how popcorn pops. A diagram related to the process of popping (which involves heat and pressure as key factors in popping kernels) would logically illustrate that mechanism. Option A is about growing/harvesting which isn't the main focus of "how it pops". Option B is about nutrition/butter - not relevant to the popping process. Option D is about types of corn - the article's main question is "how does it pop" not distinguishing corn types.

Answer:

C. It illustrates how heat and pressure cause popcorn kernels to pop.