Final answer:
Newborns' temperatures are usually measured using either axillary (under the arm) or tympanic (in the ear) methods, which are both safe and non-invasive. The axillary method is done by placing the thermometer under the armpit, while the tympanic uses an infrared ear thermometer. Rectal measurements are also used but are generally reserved for when a more accurate reading is essential.
Step-by-step explanation:
The temperature of newborns is typically measured using axillary (under the arm) or tympanic (in the ear) methods. An axillary temperature is taken by placing the thermometer under the infant's armpit, which is a noninvasive and safe method for newborns. Tympanic temperature is measured by placing an infrared ear thermometer in the infant's ear canal to measure the emitted energy, which correlates with the body's core temperature. This method is quick and reduces the risk of cross infection.
Rectal temperature measurement is another method that can be used and is often considered the most accurate for taking a newborn's core body temperature. However, due to the invasive nature of this method and the potential for injury, it is typically only used when the most accurate reading is required and cannot be obtained by other means.
In summary, the answer to the student's question would be 4) A or B, indicating that either axillary or tympanic methods can be used for measuring a newborn's temperature.