The section presents a multiple-choice question regarding chemical elements, specifically asking which of the listed options is not a metal. The options provided are:

A. Sodium (Natri)
B. Magnesium (Magie)
C. Oxygen (Oxy)
D. Gold (Vàng)

Key topics include the classification of elements as metals or non-metals, and the specific elements mentioned. The entity of focus is the identification of non-metal elements among the given choices.