Final answer:
The subject of this question is Geography, and the answer is Old Faithful.
Step-by-step explanation:
The subject of this question is Geography because it is asking about the name of a geyser, which is a geographical feature. The question is asking specifically about a geyser that was named for the predictable timing of its eruptions.
The correct answer is Old Faithful. Old Faithful is located in Yellowstone National Park in the United States and is famous for its regular and reliable eruptions.
To further understand this, it is important to know that geysers are formed when water deep underground is under high pressure and heated by magma. When the pressure is released, it causes an eruption of steam and water.