Option 1 states that both Assertion (A) and Reason (R) are true, and R is the correct explanation of A. However, this is not the case as A is false. Therefore, Option 1 is incorrect.

Option 2 states that both A and R are true, but R is not a correct explanation of A. This option is also incorrect since A is false.

Option 3 states that A is true but R is false. This option is also incorrect since A is false.

Option 4 states that A is false but R is true. This is the correct answer. India is not the largest producer of steel in the world, as indicated by A being false. However, India does have huge reserves of iron ore, which is supported by R being true.

In summary, the correct answer is option 4, as A is false but R is true.