Factors that affect enzyme action — practice question

The graph illustrates how raising substrate concentration affects the reaction rate of two enzymes that catalyse reactions using the same substrate. Which statement is the correct one?

• AEnzyme Q has a higher $K_m$ and a higher affinity for the substrate than enzyme P.
• BEnzyme Q has a higher $K_m$ and a lower affinity for the substrate than enzyme P.
• CEnzyme Q has a lower $K_m$ and a higher affinity for the substrate than enzyme P.
• DEnzyme Q has a lower $K_m$ and a lower affinity for the substrate than enzyme P.