A Shift from S₁ to S₂ Reflects the Change That $\mathrm { Q } _ { 1 }$

Multiple Choice

A shift from S₁ to S₂ reflects the change that happens when a negative externality is taken into account.A shift from D₁ to D₂ reflects the change that happens when a positive externality is taken into account.
-Refer to the above figures.An external cost exists.This will lead to a(n)

A) underproduction equal to $\mathrm { Q } _ { 1 }$ minus
$\mathrm { Q } _ { 2 }$ .
B) overproduction equal to $\mathrm { Q } _ { 4 }$ minus
$\mathrm { Q } _ { 3 }$ .
C) underproduction equal to $\mathrm { Q } _ { 4 }$ minus
$\mathrm { Q } _ { 3 }$ .
D) overproduction equal to $\mathrm { Q } _ { 1 }$ minus
$\mathrm { Q } _ { 2 }$ .