Ohm's Law Requires Linear I-V Graph Through Origin

Steps:

• Recall Ohm's law: V = IR, so I-V plot is straight line with slope 1/R passing through (0,0).
• Analyze component 1: Linear graph from origin indicates constant resistance.
• Analyze component 2: Curved or non-origin line shows varying resistance.
• Analyze component 3: Non-linear or offset graph violates proportionality.

Why D is correct:

• Component 1 alone exhibits I proportional to V (I = V/R), defining ohmic behavior.

Why the others are wrong:

• A: Components 2 and 3 lack linearity, so not ohmic.
• B: Component 2 is non-linear, violating Ohm's law.
• C: Component 3 does not pass through origin or is curved.

Final answer: D