Answer:
Supports giant impact hypothesis
• Models indicate early solar system had Mars-size leftover panetesimals
• Moon's composition is similar to Earth's mantle
• Moon has a low proportion of easily vaporized ingredients
True but not relevant to giant impact hypothesis
• Moon lacks active volcanoes
• Moon's distance is gradually increasing
• Moon has synchronous rotation (keeps same face to Earth)
Explanation:
Things to note
Models shed more light on the early solar system, the leftover planetesimals, that can cause giant impacts.
Observations of the Moon's composition reveals likelihood of formation in a giant impact, that could produce something similar to Earth's mantle layers and its low in easily vaporized ingredients (such ingredients remained gaseous and therefore would not have participated in the Moon's accretion).