The correct option is (C): Coke (C) converts \(CO _2\) to \(CO\).
Option (C) states that coke (\( \text{C} \)) converts carbon dioxide (\( \text{CO}_2 \)) to carbon monoxide (\( \text{CO} \)) in the blast furnace. This is indeed correct.
The overall reaction for this process is:
\[ \text{CO}_2 + \text{C} \rightarrow 2\text{CO} \]
This reaction occurs at high temperatures in the blast furnace, typically in the range of 900 K to 1500 K. It is an important step in the extraction of iron from its ore because carbon monoxide is a reducing agent that reacts with iron ore (\( \text{Fe}_2\text{O}_3 \)) to produce iron metal (\( \text{Fe} \)):
\[ \text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2 \]
Thus, option (C) accurately describes one of the key processes involved in the extraction of iron from its ore in the blast furnace.
Let $ P(x_1, y_1) $ and $ Q(x_2, y_2) $ be two distinct points on the ellipse $$ \frac{x^2}{9} + \frac{y^2}{4} = 1 $$ such that $ y_1 > 0 $, and $ y_2 > 0 $. Let $ C $ denote the circle $ x^2 + y^2 = 9 $, and $ M $ be the point $ (3, 0) $. Suppose the line $ x = x_1 $ intersects $ C $ at $ R $, and the line $ x = x_2 $ intersects $ C $ at $ S $, such that the $ y $-coordinates of $ R $ and $ S $ are positive. Let $ \angle ROM = \frac{\pi}{6} $ and $ \angle SOM = \frac{\pi}{3} $, where $ O $ denotes the origin $ (0, 0) $. Let $ |XY| $ denote the length of the line segment $ XY $. Then which of the following statements is (are) TRUE?
Minerals are the naturally occurring, homogeneous inorganic solid substances. They are having a definite chemical composition and crystalline structure, hardness and color. For example, copper pyrite, calamine, etc.

Impurities in an ore are called gauge. The removal of a gauge from the ore is called concentration ore.
Several steps are involved in the extraction of pure metal from ores. Major steps are as follows –