ACT English question - Need a quick explanation

<p>A growing number of states have adopted laws to prohibit dumping e-waste.</p>

<p>A. NO CHANGE
B. Adoptions are growing in state
C. States have growingly adopted
D. Growing states have adopted numbers</p>

<p>I got this question right (the answer is A), but i had a tough time choosing between A and C. Does anyone care to explain?</p>

<p>It’s the number of states that is growing. Choice C has the adverb “growingly” which would modify the word adopted, which suggests that it’s the act of adoption that’s growing and not the number of states?</p>

<p>“growingly” as used in choice C could mean that laws prohibitng e-waste are starting to “grow” in certain states, whereas “a growing number” refers to an <em>amount</em> of states that are increasing.</p>