Final answer:
A transporter protein with higher affinity for glucose than galactose will have a smaller Km for glucose, indicating its more efficient glucose transport. The correct option is A.
Step-by-step explanation:
If a transporter protein transports glucose much better than galactose, then we should expect that its Km for glucose should be much smaller than for galactose. The Km value, or Michaelis constant, is a measure of the affinity of the transporter for its substrate; a lower Km indicates a higher affinity, meaning less substrate is needed to saturate the transporter.
Therefore, a smaller Km for glucose implies that the transporter has a higher affinity for glucose, enabling it to transport glucose more efficiently than galactose.