Conjugate acid of a very strong base is relatively ...............

Explanation

The strength of a base and its conjugate acid are inversely related. When a base is very strong, it easily accepts protons, meaning its conjugate acid does not easily donate protons, making it a very weak acid. Option B is correct because it aligns with this concept. A strong acid (Option A) is incorrect because a very strong base cannot form a strong conjugate acid. Neutral (Option C) is also incorrect since conjugate acids/bases are not inherently neutral. Option D is incorrect because it suggests a contradiction: a substance cannot be both a strong and weak acid simultaneously.