Refer to the Figure Shown

Refer to the figure shown. Fish were housed under three different temperature conditions. Their response to acute and chronic temperature changes is plotted on the figure.
What will happen to line IV as temperature continues to increase beyond the scale of the visible x axis?

A) The line will continue along the same slope indefinitely.
B) The line will slope downward at 30°C until it reaches 0.
C) The line will continue along the same slope, but ultimately turn downward.
D) The line will increase along slope it reached at 30°C until the animal dies.