The correct answer is the 3rd option Ductility is a property of a metal. It is the ability of a material to deform under tensile stress.It is characterized by the ability to be stretched into wire-like form which is an ability of metals.
It is stored in the bonds between atoms.
Apples turn brown when exposed to air because it undergoes aerial oxidation. Due to this, when the inside of the apple is exposed to the air containing oxygen and water, it turns brown. When apple is uncut, skin of the apple protects it from this process.
If the peeled apple in kept in the refrigerator, the oxidation reaction is greatly slowed down. This is because, rate of chemical reaction decreases with temperature. Hence, in refrigerator it would take several days for it to turn brown.