Correct Answer:

D: Iodine

Explanation of Options:

Option A: Carbon  
 • Incorrect. Carbon is a non-metal, but it is not typically lustrous.
 • It is usually found in forms like graphite and diamond, where graphite is dull and diamond is shiny due to its crystal structure.
 • The lustrous appearance of diamond is due to its ability to refract light, not because it is inherently lustrous as a non-metal.

Option B: Silicon  
 • Incorrect. Silicon is a metalloid, not a non-metal.
 • It has a shiny, metallic luster, but its classification as a metalloid disqualifies it from being the correct answer.
 • Silicon is used in electronics due to its semi-conductive properties.

Option C: Germanium  
 • Incorrect. Germanium is also a metalloid, similar to silicon.
 • It has a metallic luster but is not classified as a non-metal.
 • Germanium is used in semiconductors and has properties between metals and non-metals.

Option D: Iodine  
 • Correct. Iodine is a non-metal that is lustrous.
 • It appears as a shiny, dark gray or purple solid at room temperature.
 • Iodine's lustrous appearance is due to its crystalline structure, which reflects light.