Which of the following would correctly indicate a weak acid's behavior?

The behavior of a weak acid is best indicated by a low acid dissociation constant (Ka) and a high pKa value. A weak acid does not completely dissociate in solution, which is reflected in its low Ka value. The pKa is the negative logarithm of the Ka; therefore, a low Ka leads to a high pKa. This relationship illustrates that the acid does not release a significant amount of hydrogen ions (H⁺) compared to strong acids, resulting in a less acidic solution.

In the context of weak acids, the high pKa value indicates that the acid is less likely to donate protons, supporting its classification as a weak acid. Consequently, the combination of a low Ka and high pKa correctly describes the characteristics of a weak acid's behavior in solution.