When should you capitalize the first letter of a word?

Capitalizing the first letter of a word is essential for clarity and correctness in writing. The correct answer is rooted in the fundamental rules of English grammar. Words should be capitalized at the beginning of a sentence to signal the start of a new thought or statement, making it easier for the reader to understand the structure and flow of the writing. Additionally, proper nouns – which name specific people, places, organizations, or things – are capitalized to signify their uniqueness and importance. This practice helps distinguish general terms from specific names, enhancing communication and comprehension.

Other choices would misrepresent the rules of capitalization; for example, capitalizing only in headlines is limited and not applicable to general writing, while capitalizing all adjectives or all nouns is unnecessarily broad and not in line with standard English usage. Thus, option B accurately represents the proper contexts for capitalization.