The maximum temperature that can be achieved in blast furnace is :

The question asks for the maximum temperature that can be achieved in a blast furnace.

In a blast furnace the temperature is limited by the thermodynamics of the combustion of coke and the heat‑transfer characteristics of the furnace lining. The primary reactions are:

$2C\; +\; O₂\; \to \; 2CO\; \hspace{1em}\Delta H\; =\; -221 kJ mol⁻¹$

and

$CO\; +\; ½ O₂\; \to \; CO₂\; \hspace{1em}\Delta H\; =\; -283 kJ mol⁻¹$

These exothermic reactions provide the heat needed to melt iron. However, the refractory lining (typically magnesite‑based) begins to soften and lose strength at temperatures above roughly 2200 K. To maintain structural integrity and to avoid rapid wear, the furnace is operated below this limit.

Consequently, the practical maximum temperature attainable in a blast furnace is about 2200 K. This is why the correct choice is “upto 2200 K”.