a) True
A yarn is a long, continuous thread made of fibres. A yarn can be used to make a fabric.
Hence, the given statement is true.
b) False
Spinning is the process of making yarn from fibres. It is the process of drawing out and twisting fibres to join them firmly together in a continuous thread or yarn.
Therefore, the given statement is false.
c) False
Coir is the fibre obtained from the outer covering of coconut. Jute is a plant fibre is obtained from stems of jute plant.
Therefore, the given statement is false.
d) True
The process of removing seeds from cotton fibres is called ginning. Ginning was traditionally done by hand. These days, machines are also used for ginning.
Therefore, the given statement is true.