The given question requires us to match the isotopes (List I) with their respective applications (List II) and select the correct answer using the provided code.

Let`s analyze each option:

Option 1:

A (Carbon) is matched with 2 (Calculation of age of the earth)

B (Cobalt) is matched with 2 (Calculation of age of the earth)

C (Iodine) is matched with 1 (Treatment of goiter)

D (Uranium) is matched with 4 (Fuel in nuclear reactors)

Option 1 matches Carbon and Cobalt with the incorrect application. Iodine and Uranium are correctly matched.

Option 2:

A (Carbon) is matched with 2 (Calculation of age of the earth)

B (Cobalt) is matched with 2 (Calculation of age of the earth)

C (Iodine) is matched with 1 (Treatment of goiter)

D (Uranium) is matched with 3 (Treatment of cancer)

Option 2 correctly matches Carbon, Cobalt, and Iodine with their respective applications. However, Uranium is matched with the incorrect application.

Option 3:

A (Carbon) is matched with