Explanation: For a sine wave, the average value is usually considered over a half-cycle, as the average over a full cycle is zero. This "rectified average" is approximately 0.636 times its peak value. Therefore, the ratio of peak to average value can be expressed as: 1. **Peak to Average = 1 / 0.636 ≈ 1.57.** So, the ratio is **1.57 to 1** (Option A). This means the peak is about 1.57 times larger than the average. 2. Alternatively, if the peak is set to 1, the average value is 0.636. So, the ratio of peak to average is **1 to 0.636** (Option B). This expresses the same relationship, just with the peak normalized to 1. Both A and B correctly describe the mathematical relationship between the peak and average values of a sine wave. Option C is incorrect because the peak and average values are not equal. Thus, D is the correct answer.