Final answer:
The crust of Earth and the crust of the Moon are closest in overall chemical composition, as both are terrestrial bodies with a rocky makeup primarily consisting of silicates.
Step-by-step explanation:
The pairs of objects that are closest to one another in overall chemical composition is (c) the crust of Earth and the crust of the Moon. Both Earth and the Moon are categorized as terrestrial bodies, primarily composed of rock and metal. Silicates made of silicon and oxygen predominantly constitute the crusts of these bodies, and they share similar geological features such as craters and mountains.
The Earth's Moon is often discussed alongside the inner terrestrial planets which include Mercury, Venus, Earth, and Mars, as they are all relatively small worlds with primarily rocky compositions.
The Moon's crust and the crusts of the terrestrial planets bear records of their geological histories, which are influenced by various forces such as volcanic activity and impact cratering. Given that the Moon and Earth have formed in the same region of the solar system, their compositions are markedly similar in comparison to the other pairs listed, which involve significant differences between gas giants, icy Kuiper Belt objects, and others.