Question

Complete the sentence with a suitable option:
According to the passage, one reason that the distribution of blood in the sea snake hardly changes while the creature remains in the ocean is that _____________

• A. The heart of the sea snake tends to be located near the center of its body.
• B. Pressure gradients in the water surrounding the sea snake counter the effects of vertical pressure gradients within its blood vessels.
• C. The sea snake assumes a vertical posture less frequently than do the terrestrial and the arboreal snake.
• D. The sea snake often relies on waves of muscle contractions to help move blood from the torso to the head.
• E. The force of pressure gradients in the water surrounding the sea snake exceeds that of vertical pressure gradients within its circulatory system.

Answer 1

Answer: (B)

Pressure gradients in the water surrounding the sea snake counter the effects of vertical pressure gradients within its blood vessels.

Option B is the right answer because it is clearly illustrated in the second paragraph of the passage that - 'Because the vertical pressure gradients within the blood vessels are counteracted by similar pressure gradients in the surrounding water, the distribution of blood throughout the body of sea snakes remains about the same regardless of their orientation in space, provided they remain in the ocean.'

There is no evidence in the passage to suggest that Options A, C, D, and E are the right answers.

Hence, these are incorrect.