निम्नलिखित में से किसे मोनेल धातु (Monel metal) का प्राथमिक नुकसान माना जाता है?

Match the following alloying elements with their effects on the properties of steel: A. Copper - (iii) Improves corrosion resistance but reduces ductility B. Nickel - (i) Improves impact toughness and cold brittle tendency C. Manganese - (iv) Increases strength but reduces weldability D. Aluminium - (ii) Increases strength Select the correct match:

Which of the following is NOT classified as a fundamental engineering property category of materials?