Scientists estimate that the Sun formed from a nebula with 71.1% hydrogen and 27.4% helium. Current measurements of the outermost layer of the Sun, the photosphere, indicate that this layer is made up of 74.9% hydrogen and 23.8% helium. However,
the core of the Sun contains about 38% hydrogen and 60% helium.
Which conclusion about the Sun is best supported by this information?