Which of the following components can cause a parasitic draw?

A parasitic draw refers to an electrical load that continues to draw power from the battery even when the vehicle is turned off. Among the listed choices, leaving the headlights on is a direct cause of such a draw. When headlights remain illuminated after the vehicle is shut down, they will deplete the battery's charge over time. This excessive drain can lead to a failure to start the vehicle, as the battery may become significantly discharged without the opportunity for it to recharge.

Battery terminals, while crucial for maintaining a good electrical connection in the system, do not inherently cause a parasitic draw themselves. They can, however, contribute to electrical issues if they are corroded or loose, leading to poor system performance. Oxygen sensors and fuel injectors are components that function when the vehicle is operating but do not continue to draw power continuously when the vehicle is turned off under normal circumstances, thus they do not typically contribute to parasitic draw issues.