According to the Brønsted–Lowry definition, what is a base?

• A. An electron-pair acceptor
• B. A proton ($H^{+}$) donor
• C. A proton ($H^{+}$) acceptor
• D. A substance that produces $O^{H_{\mathrm{-}}}$ ions in water

Answer: (C)

Verified step by step guidance

1. Recall the Brønsted–Lowry acid-base theory, which defines acids and bases based on proton transfer.
2. According to this theory, an acid is a substance that donates a proton (H\^+), so a base must be the substance that accepts a proton.
3. Identify that a proton (H\^+) acceptor is the correct definition of a Brønsted–Lowry base.
4. Note that the other options, such as electron-pair acceptor or substances producing OH\^− ions, correspond to different acid-base theories (Lewis and Arrhenius, respectively).
5. Conclude that the Brønsted–Lowry base is specifically a proton (H\^+) acceptor.