The figure below shows three white dwarfs on an HR diagram.Which of these three is oldest? 
Definitions:
Equator
An imaginary line around the Earth equidistant from the poles, dividing it into northern and southern hemispheres and marking the 0-degree latitude line.
Tropical Rain Forest
A dense, warm, wet forest biome found near the equator, known for its high biodiversity and significant rainfall.
High Annual Rainfall
A climatic condition where a region receives a significantly large amount of precipitation over the course of a year.
Freezing Temperatures
A temperature at or below the freezing point of water, 0°C (32°F), where liquid water turns into ice.
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