Select ALL components that can form a buffer solution.

### Why this is right - **A weak acid and its conjugate base**: the acid can donate protons and the conjugate base can accept them, helping resist pH change. - **A weak base and its conjugate acid**: the base can accept protons and the conjugate acid can donate them. ### The concept A buffer works because it contains both members of a conjugate pair in useful amounts. Added acid or base is partly consumed by the appropriate buffer component. ### The other options - **A strong acid alone**: it dissociates extensively and does not provide a weak conjugate pair to resist pH change. - **A strong base alone**: it also lacks the appropriate conjugate pair. ### Terms - **Buffer**: a solution that resists changes in pH when limited acid or base is added. ### Remember A buffer needs a weak species and its conjugate partner.