Final answer:
The normal level of urea nitrogen in adults, which is 7-18 mg/dL, when converted to ppm is 70-180 ppm; therefore, the correct range in ppm is option B (70-180 ppm).
Step-by-step explanation:
The normal level of urea nitrogen in adults is 7-18 mg/dL. To convert this range to parts per million (ppm), we consider that 1 mg/dL is equivalent to 10 ppm because 1 deciliter (dL) is 1/10th of a liter (L) and there are 1,000,000 mg in a liter (which defines ppm).
Therefore, we simply multiply the values by 10 to get the correct range in ppm.
So, for the provided range:
- 7 mg/dL × 10 = 70 ppm
- 18 mg/dL × 10 = 180 ppm
Hence, the correct range in ppm for the normal level of urea nitrogen in adults is 70-180 ppm, making the answer option B (70-180 ppm).