In a paper chromatography experiment, an $R_f$ value is determined for $\text{Fe}^{3+}(aq)$. The outcome is shown. To make the spot containing $\text{Fe}^{3+}(aq)$ easier to see, the paper is sprayed with aqueous sodium hydroxide, causing a precipitate of iron(III) hydroxide to form. For the conditions used in the experiment, the $R_f$ of $\text{Fe}^{3+}(aq)$ is ______ and the colour of the precipitate is ______. Which row correctly fills gaps 1 and 2?
- Agap 1: $\frac{x}{y}$; gap 2: red-brown
- Bgap 1: $\frac{x}{y}$; gap 2: green
- Cgap 1: $\frac{y}{x}$; gap 2: red-brown
- Dgap 1: $\frac{y}{x}$; gap 2: green