Step 1: Understanding the Concept:
Identify the correct orthography for a complex biological/aesthetic term. Step 2: Key Formula or Approach:
Approach: Break the word into syllables: Pul-chri-tu-di-nous. Step 3: Detailed Explanation:
Option D matches the standard dictionary spelling for this word, which means physical beauty.
Other versions introduce unnecessary vowels (Pulchiritudinous) or omit letters. Step 4: Final Answer:
The correct spelling is Pulchritudinous.