Fill in the blanks given the image.

ggplot$($diamonds$)+$

geom$\_$smooth$($aes$($carat$,$ price, $\_\_\_\_\_=$ cut$))+$

geom$\_$point$($aes$($carat$,$ price, $\_\_\_\_\_=$ cut$))$

I have the second one as color but can't figure out the first one. I've tried: price, cut, color, fill, size, carat...none of them work! give me the solution to this