In and iron-carbon alloy, the content of carbon is state to be 4.3 percent. Such a cast iron is know as-

Correct option is C

In the iron-carbon system, the eutectic composition occurs when the carbon content is approximately 4.3% by weight. At this composition, the alloy solidifies at the eutectic temperature of 1147°C, forming a microstructure of austenite and cementite (ledeburite). This is known as eutectic cast iron, as it corresponds to the eutectic point in the iron-carbon equilibrium diagram.
· Hypo eutectic cast iron refers to cast iron with carbon content less than 4.3%, but more than 2% (e.g., 3.5% C).
· Hyper eutectic cast iron refers to cast iron with carbon content greater than 4.3% (e.g., 4.5% C).
· At exactly 4.3% C, the alloy is termed eutectic cast iron.