Single-celled organisms, called oceans today, and are capable of converting
through photosynthesis. *
into energy
A. land plants; oxygen
B. land plants; sunlight
C. phytoplankton; oxygen
D. phytoplankton; sunlight

The correct answer is B.Their numbers have increased because of the Endangered Species Act and E.They are an example of protecting biodiversity through the passage of laws.

Explanation:

Gray whales are nearly 45 meters long baleen whales live in the pacific ocean. Gray whale species were on the line of extinction due to overhunting or whaling in the mid 90's but due to the protection given under Endangered Species Act, its number increased now to 25,000 and in 1994 it was removed from endangered species list.

Endangered Species Act's purpose is to protect those animals and plants which are at the risk of extinction and increase their number in the wild. It is the strongest law implemented to save biodiversity.  

So gray whale species have increased due to the Endangered Species Act which is an example of protecting biodiversity through the passage of laws. Therefore the correct answer is B and E.