<p>The correct answer is <strong>(B) Among</strong>.</p>
<p>In this sentence, we are talking about the firm's notable achievement, which is the opening of a new research and development center in Seoul. The word "among" is used to show that this achievement is part of a group or collection of achievements. It implies that there are other notable achievements as well, but this one stands out among them.</p>
<p>The preposition "into" (option A) is not the correct choice here because it suggests movement or direction, indicating that the firm physically moved into the research and development center in Seoul. However, the sentence is simply stating that the opening of the center was a notable achievement.</p>
<p>The preposition "despite" (option C) is also not the correct choice because it indicates that the opening of the center was achieved despite some obstacle or difficulty. However, the sentence does not provide any information about obstacles or difficulties that were overcome.</p>
<p>The preposition "around" (option D) is not the correct choice because it suggests a general area or vicinity. However, the sentence is specifically referring to the opening of a new research and development center in Seoul, which is a specific location.</p>