Answer
We can rank them according to their end to end resistances:
$A = B = C \gt (A+B) = (B+C) \gt (A+B+C)$
Work Step by Step
$R = \frac{\rho~L}{A}$
Since the conductors are made of the same material, the conductivity $\rho$ is the same for all three conductors.
Also, it is given that the three conductors have the same length $L$
We can write an expression for the resistance of each of the given options:
$A$:
$R = \frac{\rho~L}{A} = \frac{\rho~L}{3l^2-2l^2} = \frac{\rho~L}{l^2}$
$B$:
$R = \frac{\rho~L}{A} = \frac{\rho~L}{2l^2-l^2} = \frac{\rho~L}{l^2}$
$C$:
$R = \frac{\rho~L}{A} = \frac{\rho~L}{l^2}$
$A+B$:
$R = \frac{\rho~L}{A} = \frac{\rho~L}{3l^2-l^2} = \frac{1}{2}\cdot \frac{\rho~L}{l^2}$
$B+C$:
$R = \frac{\rho~L}{A} = \frac{\rho~L}{2l^2} = \frac{1}{2}\cdot \frac{\rho~L}{l^2}$
$A+B+C$:
$R = \frac{\rho~L}{A} = \frac{\rho~L}{3l^2} = \frac{1}{3}\cdot \frac{\rho~L}{l^2}$
We can rank them according to their end to end resistances:
$A = B = C \gt (A+B) = (B+C) \gt (A+B+C)$
