Final answer:
Gold, with symbol Au, is the yellow, nonreactive, metallic element renowned for its beauty and durability, primarily used in jewelry and as currency. Therefore, correct option is a.
Step-by-step explanation:
The yellow, nonreactive, metallic element that has been highly valued since ancient times for its beauty and durability is gold. Gold, with the chemical symbol Au, is notable for its softness, malleability, lustrous appearance, and excellent conductivity of electricity and heat.
It has been used throughout history for various purposes, particularly in making jewelry, due to its unreactive nature, which means it does not easily corrode or react with other substances. This makes gold jewelry a symbol of wealth as it maintains its appearance over time without tarnishing.
Additionally, gold is used as currency which further highlights its value. Gold is a noble metal and is often found in elemental form in nature, which made it one of the first metals to be used by humans. Ancient civilizations valued gold highly, utilizing it for ornamental and monetary purposes and even linking it to deities and royalty.