A customer notifies the integrator that the system keypad reports trouble at a window. Upon inspection， the customer finds the window closed and locked； the customer resets the system and it fails to correct the issue. Which of the following steps should the integrator take to resolve the issue？（）

• A、Check that the sensor is not misaligned.
• B、Clean the space between the sensor and the plate.
• C、Toggle the tamper switch to reset the sensor.
• D、Bypass the zone.