Answer: Co-formation Theory
Step-by-step explanation:
There are three theories which hypothesis the formation of moon:
Giant impact hypothesis- moon was formed out of the collision of Mars-sized body and Earth.
Co-formation theory - moon was formed along the Earth from the dust of the solar Nebula. Proto-moon was close to Proto-Earth, hence, they have similar rocky composition.
Capture theory- Moon (a rocky body ) was captured by Earth's gravity.
Mr. Harris stated that the moon and the earth formed at the same time from dust from the solar nebula. Thus, He is describing Co-formation theory.