Analogy

Step 1: Identify the relationship in the given pair. The earth is described in terms of its shape, which is like a ball. Thus, the relationship is based on resemblance of shape.
Step 2: Apply the same relationship to the second pair. A pancake is similarly described by its shape, which resembles a disc.
Step 3: The option that correctly preserves this shape-based analogy is option (C), as it expresses the same relationship.