<p>If you buy two books from Pixar online bookstore today, you will obtain <strong>another</strong> for free.</p>
<p>The correct answer is <strong>(B) another</strong>.</p>
<p>In this sentence, the word "another" is used to indicate that you will receive an additional book for free when you buy two books. "Another" is the appropriate word choice here because it means "one more" or "an additional one".</p>
<p>The other options can be ruled out:</p>
<p>(A) "it" is incorrect because it does not refer to a specific noun in the sentence. "It" is a pronoun that is used to refer to a previously mentioned noun, but there is no noun in the sentence that "it" could refer to.</p>
<p>(C) "each other" is incorrect because it is used to refer to two or more people or things that are doing something to or with each other. In this sentence, there is no indication that the books are doing something to or with each other.</p>
<p>(D) "one another" is incorrect for the same reason as (C). "One another" is used to refer to a reciprocal action between two or more people or things. In this sentence, there is no reciprocal action happening between the books.</p>