Which of the following is a property-enhancing operation: a) drilling b) extrusion c) forging d) grinding el heat treatment f) painting o \( a \)

To determine which of the given operations is a property-enhancing operation, we need to understand what property-enhancing operations are. Property-enhancing operations are processes that improve the properties of a material, such as its strength, hardness, or corrosion resistance. Let's analyze each of the given operations: a) Drilling: Drilling is a process of creating a hole in a material. It does not enhance any properties of the material. b) Extrusion: Extrusion is a process of shaping a material by forcing it through a die. It can enhance properties such as strength and hardness. c) Forging: Forging is a process of shaping a material by applying heat and pressure. It can enhance properties such as strength and hardness. d) Grinding: Grinding is a process of removing material from a surface. It does not enhance any properties of the material. e) Heat treatment: Heat treatment is a process of altering the properties of a material by applying heat. It can enhance properties such as strength and hardness. f) Painting: Painting is a process of applying a coating to a material. It does not enhance any properties of the material. Therefore, the property-enhancing operations among the given options are: - Extrusion (b) - Forging (c) - Heat treatment (e)