Solution:Concept- One of the rarest metals on earth, platinum is also known as the "noble metal" because it cannot be found in combination forms in the natural world. Platinum is the least reactive of all the alternatives. In the natural environment, iron and aluminium can potentially mix to produce new compounds. While platinum is not present in its mixed form in natural settings. It is also widely used in jewellery that resembles gold because of its malleable nature and glossy silvery look as well as its remarkable corrosion resistance, even at very high temperatures. The demand for electronic components is very strong.
Noble elements are the least reactive metals. They are non reactive towards moisture and water so resistant to rust and can resist high temperatures. Platinum is the least reactive.
Hence, the correct answer is option 3.