Almost every other compound in nature contracts when frozen, but H20 [water] molecules do the opposite,

organizing themselves into elegant hexagonal crystals that

take up about 9 percent more space than they did when

sloshing around in a liquid state. Pretty six-sided crystals

suggest snowflakes so gossamer it's hard to conceive of

them pushing apart slabs of sidewalk.

Which statement best describes the effect of the metaphor on the excerpt's

meaning?

It compares the frozen crystals to delicately lacy snowflakes having an unexpected strength.

Explanation:

A Metaphor may be defined as a figure of speech where a phrase or a word is applied to an action or an object to which it can not literally or directly applicable.

In the excerpt that has been given in the question, there is a direct comparison made for the frozen crystals. They look very soft and fine when we look at them but they are hard substances in real. They seems like a deceitful foe to be friends to the city.  

because he is using a description to provide evidence to support his argument.

hope this could

a is is the correct answer