A clinical thermometer reads temperature from:
(A) 35°C to 42°C
(B) 0°C to 100°C
(C) 25°C to 42°C
(D) 35°C to 62°C

The correct answer is (A) 35°C to 42°C.
Explanation:
A clinical thermometer is specifically designed to measure the body temperature of humans. It typically has a limited range of measurement, which is suited to detecting normal human body temperature variations.
1. Temperature Range:
o The usual temperature range for a clinical thermometer is from about 35°C to 42°C. This range covers the typical human body temperature, which is around 37°C for a healthy adult, and the higher end accounts for fever conditions, which can be up to 42°C or slightly higher.
2. Why Not the Other Options:
o (B) 0°C to 100°C: This range is too broad for a clinical thermometer. It is more suitable for a laboratory or industrial thermometer, which can measure the freezing point and boiling point of water.
o (C) 25°C to 42°C: This is narrower than the standard range of a clinical thermometer. It does not include the lower boundary of 35°C, which is considered the starting point for measuring body temperature.
o (D) 35°C to 62°C: This is too high for a clinical thermometer. The upper limit for body temperature typically does not exceed 42°C, and higher readings could indicate severe health conditions, not normal body temperature ranges.
Conclusion:
The correct range for a clinical thermometer is 35°C to 42°C, which allows it to measure the normal human body temperature and detect fever conditions. Therefore, the correct option is (A) 35°C to 42°C.