Out of the given options, option 4, Iodine, is the correct answer. Iodine is a non-metal but it is lustrous, which means it has a shiny or reflective appearance.
Option 1, Carbon, is a non-metal but it is not lustrous. Carbon is a dull solid in its most common form, graphite. Graphite is used in pencil leads and has a black, opaque appearance.
Option 2, Silicon, is a metalloid and not a non-metal. Metalloids have properties that are intermediate between metals and non-metals. Silicon is widely used in electronics and has a dull, metallic appearance.
Option 3, Germanium, is also a metalloid and not a non-metal. Germanium is used in semiconductors and has a shiny, metallic appearance similar to silicon.
Therefore, the correct answer is option 4, Iodine. It is a non-metal but exhibits a lustrous or shiny appearance.