Energy transfer in photosynthesis occurs as:

• A
  Phycoerythrin $\to$ Phycocyanin $\to$ Carotenoid $\to$ Chlorophyll $a$
• B
  Chlorophyll $b$ $\to$ Carotenoid $\to$ Phycoerythrin $\to$ Chlorophyll $a$
• C
  Phycocyanin $\to$ Phycoerythrin $\to$ Carotenoid $\to$ Chlorophyll $a$
• D
  Chlorophyll $b$ $\to$ Carotenoid $\to$ Chlorophyll $a$