Which metal alloy is primarily composed of 90% copper along with tin and sometimes zinc?

The correct choice indicates an alloy known as bronze, which is primarily composed of copper and typically includes tin as its main alloying element. When the alloy consists of around 90% copper and varying amounts of tin, it is classified as bronze. This composition imparts the material with characteristics such as increased strength and resistance to corrosion, making it suitable for various applications, including sculpture, musical instruments, and coins.

While gold, silver, and aluminum are significant metals, they do not fit the description provided in the question regarding an alloy made primarily of copper and tin. Gold and silver are both pure metals, and while they can be alloyed, they do not contain copper in their standard forms. Aluminum is also a distinct metal and is not typically associated with a high copper content in its common alloys. Hence, bronze stands out as the only relevant alloy in this context.