Which of these refers to cooking food in liquid at a temperature just below the boiling point?

Simmering is a food preparation technique by which foods are cooked in hot liquids kept just below the boiling point of water (lower than 100 °C or 212 °F) and above poaching temperature (higher than 71–80 °C or 160-180 °F).

To create a steady simmer, a liquid is brought to a boil, then its heat source is reduced to a lower, constant temperature.

Simmering is usually a rapid and efficient method of cooking. Food that has simmered in milk or cream instead of water is sometimes referred to as creamed. The appropriate simmering temperature is a topic of debate among chefs, with some contending that a simmer is as low as 82 °C (180 °F).