Explanation: Frequency counter accuracy is often expressed in parts per million (ppm). This value indicates the maximum possible deviation from the true frequency due to the accuracy of the counter's internal time base. To calculate the maximum possible difference, you multiply the measured frequency by the ppm value expressed as a decimal. In this case: 1.0 ppm = 1.0 / 1,000,000 = 0.000001 Maximum difference = 156,520,000 Hz * 0.000001 = 156.52 Hz. This means the actual transmitter frequency could be 156.52 Hz higher or lower than the reading on the frequency counter. Option C correctly reflects this calculation. Options A, B, and D represent significantly different error margins that do not match a 1.0 ppm accuracy at this frequency.