Concept:
Fabric deformation refers to unwanted changes in shape, alignment, or structure of textile material due to stress, tension, or improper handling during manufacturing or use.
Step 1: Understand deformation.
When fabric surface is disrupted:
• Yarn alignment is disturbed
• Structural geometry changes
• Fabric loses original form
Step 2: Analyze options.
• Slubs → yarn defect
• Seam elasticity → stretch property
• Seam grain → alignment reference
• Distortion → change in fabric shape (correct)
Step 3: Final conclusion.
\[
\boxed{\text{Distortion}}
\]
Thus,
\[
\boxed{\text{Option (C) is correct.}}
\]