Correct option is A
Countersinking is the process of enlarging and beveling the top portion of an existing hole to allow the head of a screw or bolt to sit flush with or below the surface of the material. This process is commonly used in applications where a flat or smooth surface is required after fastening.
Countersinking is typically performed using a countersink tool or drill bit, which creates a conical recess at the hole’s entrance. This is particularly useful for accommodating flat-head screws, rivets, or bolts.
Spot Facing is used to create a flat surface around a hole, ensuring a proper seating surface for bolts, nuts, or washers. Unlike countersinking, it does not create a conical recess.
