In a reaction progress curve, which point on the curve corresponds to an intermediate of the reaction?

the point at the far left of the curve

a valley between two peaks

the top of a peak

the point at the far right of the curve

So are u adding some additional catalyst

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips.