Which tools are commonly used for temperature observation?

Thermometers and psychrometers are specifically designed to measure temperature and provide relevant readings for atmospheric conditions. Thermometers directly measure the temperature of air, water, or other substances. They are fundamental tools in meteorology and are used extensively for calculating weather conditions. Psychrometers, which consist of two thermometers (a dry bulb and a wet bulb), are used to determine the relative humidity but also enable the calculation of air temperature through the use of the wet bulb temperature.

In this context, the combination of these two types of instruments makes option B the most appropriate choice for temperature observation, as one measures the temperature directly while the other provides additional information that can correlate to temperature readings.

Other options consist of tools that focus on different atmospheric aspects, such as pressure, humidity, wind speed, or altitude, which do not directly pertain to temperature measurement.