Answer
The most appropriate representation is in the drawing number $(iii)$
Work Step by Step
Originally, we have a weak acid solution.
- So it can't be drawing $(ii)$. Because the pH is too high. (At the start).
Since this is not a polyprotic acid, it has only one equivalence point.
- So it can't be drawing $(iv)$.
Now, we have $(i)$ and $(iii)$.
Normally, the pH of a pure weak solution is higher than the one for a strong acid (same concentrations), therefore, the most appropriate one is the $(iii)$, because it has a higher initial pH.
