" The three sewing machine parts which together constitute the drop feed mechanism are:

Correct option is B

The drop feed mechanism in a sewing machine is composed of the presser foot, throat plate, and feed dog. This mechanism allows the fabric to move beneath the needle while stitching. The feed dog, located beneath the throat plate, moves the fabric in sync with the machine's needle. The presser foot holds the fabric in place, ensuring a consistent and smooth flow during stitching. Together, these components control the movement of the fabric and ensure precise stitching.
Information Booster:
The drop feed mechanism is a standard feature in most household sewing machines. It helps with even feeding of fabric during stitching and allows the machine to create straight, evenly spaced stitches. This is essential for consistent seam quality in garment construction and other sewing projects. The mechanism also enables the use of different fabric types, from lightweight to heavy, by adjusting the pressure of the presser foot.
Additional Knowledge:
(a) Needle, thread take-up level, presser foot: These parts are essential for stitching, but they are not part of the drop feed mechanism. The thread take-up lever helps control the thread tension, and the needle is responsible for piercing the fabric, but they do not move the fabric.
(c) Needle bar, spool, feed dog: The needle bar and spool are involved in holding and guiding the thread, but they are not part of the fabric feeding mechanism.
(d) Bobbin, needle, throat plate: The bobbin holds the lower thread, and the needle performs the stitching, but neither part is directly involved in moving the fabric as part of the drop feed system.