Question

Match List I with List II:

List I (Substances)	List II (Element Present)
(A) Ziegler catalyst	(I) Rhodium
(B) Blood Pigment	(II) Cobalt
(C) Wilkinson catalyst	(III) Iron
(D) Vitamin B12	(IV) Titanium

Choose the correct answer from the options given below :

• A. A-II, B-IV, C-I, D-III
• B. A-II, B-III, C-IV, D-I
• C. A-III, B-II, C-IV, D-I
• D. A-IV, B-III, C-I, D-II

Answer 1

The Correct Option is D

The question requires us to match substances with the elements present in them. Let's analyze each pair: 

1. Ziegler Catalyst: The Ziegler catalyst is widely used in the polymerization of ethylene and other alpha-olefins, and it primarily contains Titanium (IV). Therefore, the correct match for Ziegler catalyst is (IV) Titanium.
2. Blood Pigment: The main pigment in blood is hemoglobin, which contains the element Iron (Fe) incorporated in its structure. Hence, the correct match for Blood pigment is (III) Iron.
3. Wilkinson Catalyst: The Wilkinson catalyst is a chemical catalyst known for hydrogenation reactions, and it contains Rhodium (I). Therefore, the correct match for Wilkinson catalyst is (I) Rhodium.
4. Vitamin B12: Vitamin B12, also known as cobalamin, contains the element Cobalt (Co) in its structure. Thus, the correct match for Vitamin B12 is (II) Cobalt.

Thus, the correct combination is:

List I (Substances)	List II (Element Present)
(A) Ziegler catalyst	(IV) Titanium
(B) Blood Pigment	(III) Iron
(C) Wilkinson catalyst	(I) Rhodium
(D) Vitamin B12	(II) Cobalt

Therefore, the correct answer is: A-IV, B-III, C-I, D-II

Answer 2

Ziegler catalyst → Titanium
Blood pigment (hemoglobin) → Iron
Wilkinson catalyst → Rhodium
Vitamin B₁₂ → Cobalt
Thus, the correct matching is:
A-IV, B-III, C-I, D-II
So, the correct answer is: Option (4)