Match List-I with List-II:

List-I (Pigment)	List-II (Associated with)
(A) Phytochrome	(I) Stimulation of flowering
(B) Leghemoglobin	(II) Nitrogen fixation
(C) Chlorophyll a	(III) Red algae
(D) Chlorophyll d	(IV) All photosynthesizing plants except bacteria

Choose the correct answer from the options given below:

Correct option is A

The correct answer is (A) (A)-(I), (B)-(II), (C)-(IV), (D)-(III)

Explanation:
• Phytochrome (A) is a pigment involved in photomorphogenesis, primarily responsible for the stimulation of flowering (I) and seed germination based on light duration (photoperiodism).
• Leghemoglobin (B) is an oxygen scavenger found in the root nodules of leguminous plants, creating anaerobic conditions necessary for Nitrogen fixation (II) by the enzyme nitrogenase.
• Chlorophyll a (C) is the universal photosynthetic pigment found in all photosynthesizing plants except bacteria (IV). It is the primary reaction center pigment.
• Chlorophyll d (D) is a specific form of chlorophyll found primarily in Red algae (III) (Rhodophyta) and some cyanobacteria.

Information Booster:
• Phytochrome exists in two interconvertible forms: Pr (red light absorbing) and Pfr (far-red light absorbing).
• Leghemoglobin gives the inside of healthy root nodules a pinkish/reddish color.

Additional Knowledge:
• Options B, C, and D are incorrect as they misplace the universal role of Chlorophyll a or the specific occurrence of Chlorophyll d in red algae. For example, leghemoglobin has no role in Red algae (III).