The correct option is C Mercury, Neptune
Mercury has the shortest year (88 Earth days), and Neptune has the longest year (165 Earth years). Planets closer to the Sun have shorter year, because their orbits are smaller. Mercury, the innermost planet in the solar system, completes an orbit in 88 days. The farther away a planet is from the Sun, the slower its orbital motion becomes. Neptune is the eighth planet from the Sun, takes longer time to complete one revolution around the Sun.