Answer – C (Using instruments that have not been calibrated).
When the integrity of an instrument’s calibration has been compromised (usually due to exposure to a shock, vibration, or physical damage), it needs to be calibrated; failure to do this inevitably leads to inaccurate measurement; this is a very common measurement error.
It would appear to rise from the horizon to 10° above the horizon. Keep gong north until you reach the North Pole and the pole star will appear directly overhead.
