Which of the following is the most abundant element in the earth's crust?

Oxygen is the most abundant element in Earth's crust, comprising approximately 46-47% by mass. It is found in silicate minerals, oxides, water, and atmospheric oxygen. Silicon is the second most abundant (~28%), followed by aluminium (~8%), then iron (~5%). Sulphur, Potassium, and Magnesium are present in much smaller quantities.