The $V-I$ graph for series and parallel combination of two metallic resistors is as shown in the figure. Which graph represents parallel combination? Justify your answer.

(A) According to Ohm's law, $V = IR$, which implies $R = V/I$.
In a $V-I$ graph, the slope of the line represents the resistance $(R = \text{slope} = \tan \theta)$.
Graph $A$ has a smaller slope compared to graph $B$, which means graph $A$ represents a lower resistance.
In a parallel combination of resistors, the equivalent resistance is always less than the individual resistances, whereas in a series combination, the equivalent resistance is greater than the individual resistances.
Therefore, graph $A$ represents the parallel combination because it corresponds to the lower resistance value.