Ohm's Law: Current proportional to voltage for fixed resistance

Steps:

• Apply Ohm's Law: V = I * R, so I = V / R with R constant.
• Rearrange shows I directly proportional to V, yielding linear relationship.
• Graph of I versus V is straight line through origin with slope 1/R.
• Select option depicting this linear plot.

Why A is correct:

• Matches Ohm's Law formula, showing direct proportionality as straight line from (0,0).

Why the others are wrong:

• B: Nonlinear curve implies varying resistance, not constant.
• C: Inverse or decreasing trend contradicts positive proportionality.
• D: Flat or unrelated shape ignores voltage dependence.

Final answer: A