What indicates a low pH in terms of H+ ions?

A low pH indicates a high concentration of hydrogen ions (H+) in a solution. The pH scale ranges from 0 to 14, where values below 7 represent acidic conditions, characterized by increased H+ ions. The presence of more H+ ions makes the solution more acidic, thus lowering the pH. This relationship is fundamental in understanding acid-base chemistry, as a low pH corresponds directly to a greater concentration of hydrogen ions in the solution. In contrast, neutral pH (around 7) signifies an equal concentration of H+ and hydroxide ions (OH-), while a high concentration of hydroxide ions would indicate a basic solution, which corresponds to a higher pH. Therefore, option A accurately reflects the relationship between pH and hydrogen ion concentration.