Two compounds I and II are eluted by column chromatography (adsorption of `I gt II`). Which one of the following is a correct statement ?
A. I movers faster and has higher `R_(f)` value than II
B. II moves faster and has higher `R_(f)` value than I
C. I moves slower and has higher `R_(f)` value than II
D. II moves slower and has higher `R_(f)` value than I
