Which of the following consists solely of weak acids?

The selection of weak acids in the context of this question refers to substances that do not fully dissociate in aqueous solution. Weak acids only partially ionize, resulting in a mixture of both ionized and non-ionized forms in solution.

In the option identified as correct, HF (hydrofluoric acid), HNO2 (nitrous acid), and CH3COOH (acetic acid) are all recognized as weak acids.

HF, despite being one of the stronger weaker acids due to its relatively high dissociation constant compared to many others classified as weak, does not completely dissociate in water. Similarly, HNO2 and CH3COOH both exhibit limited ionization in solution, qualifying them as weak acids.

The groups of compounds in the other options contain strong acids or bases, disqualifying them from the classification of solely weak acids. For example, HCl and H2SO4 are strong acids that completely dissociate in solution, while NaOH is a strong base. Thus, those options cannot be correct because they do not consist exclusively of weak acids.