Amongst the following compounds, which one is an antacid?

Antacids are actually alkaline ions that directly neutralize the gastric acids of the stomach. Substances such as sodium hydrogen carbonate or a mixture of aluminium and magnesium hydroxide are used as antacids. Ranitidine is an antacid.

Tranquilizers are a class of chemical compounds used for the treatment of stress, and mild or even severe mental diseases.Meprobamate is relatively mild tranquilizers suitable for relieving tension.

Synthetic drugs, brompheniramine (Dimetapp) and terfenadine (Seldane), act as antihistamines. They interfere with the natural action of histamine by competing with histamine for binding sites of receptor where histamine exerts its effect.

So, the correct answer is Ranitidine is an antacid.