Correct Answer: Boron

Solution : The correct answer is boron .

Among the options provided, boron is an example of a metalloid. Metalloids are elements that exhibit properties of both metals and non-metals. Boron is situated on the periodic table in the boron group and has characteristics that are intermediate between metals and non-metals. It displays both metallic and non-metallic properties, making it a metalloid. Indium and gallium are metals, while aluminium is a metal.