The properties listed in the description suggest that the substance is a metal. The reddish color, shiny appearance, ductility, and malleability are typical characteristics of metals. Additionally, the fact that it becomes dull when exposed to air and develops a green-colored layer in moist air indicates it might be a type of copper or a copper alloy, which is known for tarnishing and forming a green patina (copper oxide) over time.
The melting and boiling points provided (1084.62 °C for melting and 2562 °C for boiling) are also consistent with metals.
Given these properties, the correct answer is:
B metal