Using information from the diagram, state one reason why the movement of molecules in method c represents active transport.

The best way of telling wether C represents active transport and why it does so is by looking at the molecules:

In active transport the molecules go from lower concentration regions to higher concentration (referring to molecule concentration) regions, and that is what we see in the image. Outside the cell, the concentration is represented by 2 molecules while inside there are far more. What this molecules where doing, in more scientific terms, is that they where crossing the concentration gradient.

Hope it helped,

BioTeacher101

(If you have any questions, feel free to ask them in the comments)