Answer:
a)True
Step-by-step explanation:
Rolling:
Rolling is a metal forming in which a material passes through two or more than two depends on conditions,rolls to produce the desired product.
Ring rolling:
In ring rolling a thick ring compresses by rolls to produce the large diameter ring.Actually volume of material is constant so when diameter of ring increases then to compensate it, the thickness of ring reduces .In simple words we can say that in ring rolling a thick ring of smaller is rolled into a thin ring of larger diameter.