Step 1: Understanding the Concept:
Shape factor is a concept used in specific heat transfer modes.
It relates to the geometry of surfaces.
Step 2: Key Formula or Approach:
No specific formula.
Need to know where shape factor is used.
Step 3: Detailed Explanation:
Shape factor, geometrical factor, configuration factor, or view factor are used in radiation heat transfer.
They describe the fraction of radiation leaving one surface that strikes another.
Conduction and convection do not use these factors.
Thus, radiation heat transfer is the correct answer.
Step 4: Final Answer:
Shape factor is used in radiation heat transfer.
Hence, the correct option is (C).