Refer to figure.
The graphs depict the Take-Off Distance (TOD) with differing flap settings (the dotted lines are the all-engines case, AEO - All Engines Operative) and how that changes in the event of an engine failure (OEI - One Engine Inoperative).

The effect of flaps on TOD is as follows:

• Initially, increasing flap setting (from no flaps) reduces the take-off distance as the aircraft can lift-off at a lower speed, reducing the Take-Off Run.
• At a certain point though, the extra drag of high flap settings becomes a problem, as the aircraft will require more distance to accelerate and much more distance to reach the screen height. This extra distance eventually outweighs the small reduction in lift-off speeds when using high flap settings. This creates the curved pattern shown in figures 3 and 4.

The final part of this question is to work out whether TOD increases or decreases if an engine fails. If an engine fails at V_EF (the most limiting point of the take-off run), then the aircraft will have to perform the rest of the take-off and climb to screen height with half the thrust, so much less performance.

Therefore, the TOD in the OEI case is longer than in the AEO scenario, and therefore the graph moves upwards in the event of an engine failure, so the correct answer is figure 4.