Concept: One-dimensional motion and functional requirement
In one-dimensional motion, position must be a function of time:
\[
x = f(t)
\]
This implies:
• For every value of time, there must be only one position
• Graph must satisfy vertical line test
Step 1: Physical meaning of graph
• Time is independent variable
• Position (or velocity/acceleration) depends on time
Step 2: Check each option conceptually
• (A): Acceleration vs time → valid
• (B): Velocity vs time → valid straight-line motion
• (D): Position vs time → oscillatory but single-valued → valid
• (E): Position vs time → piecewise motion → valid
Step 3: Analyze option (C)
• Closed loop (ellipse-like graph)
• At same time → multiple positions
Step 4: Apply vertical line test
• Draw vertical line → intersects graph at multiple points
• Hence not a function
Step 5: Physical contradiction
• Particle cannot be at two positions simultaneously
• Violates fundamental definition of motion
Final Answer:
\[
\boxed{\text{(C)}}
\]