* Weak acids only partially ionize in solution. This means that they don't completely break apart into their ions (like strong acids do).

* The equilibrium: A weak acid, HA, will exist in an equilibrium with its conjugate base, A⁻, and hydronium ions, H₃O⁺. This can be represented by the following equation:

HA(aq) + H₂O(l) ⇌ A⁻(aq) + H₃O⁺(aq)

* Result: The solution will contain a mixture of:

* Un-ionized acid molecules (HA)

* Anions (A⁻)

* Hydronium ions (H₃O⁺)

Why the other options are incorrect:

* B. All: While weak acids do produce ions, they also have a significant amount of the undissociated acid molecules present.

* C. D anions but no hydronium ions: This is not true. Weak acids do produce hydronium ions, just in lower concentrations than strong acids.

* D. Anions but no hydronium ions: This is the same as option C.

Let me know if you have any other chemistry questions!