Answer:
Its D
Step-by-step explanation:
Because option A is wrong cause it says that seals are not smart animals but seals have nothing to do with orcas.
And B says it shows how the killer whale got its name which is not what the paragraph is about.
C describes how the killer whale swims when it hunts which is not what the paragraph even said
Therefore D makes the most sense because it says in the paragraph " The killer whales stomach blends in with the sunlight streaming down from the sea blending in with the sunlight so it makes it hard to spot from below.