This selection explains that many ocean rowers quit when all they see is " 360 degrees of just horizon." This means that rowers often turn back because (A) they are unable to see land in any direction, just sea and sky. (B) they need a clear view of the shore to navigate the ocean. (C) their view is obstructed by the line where the sea and sky meet. (D) their ship to shore communication system might be blocked.

To determine the correct answer, let's analyze the statement provided: The phrase "360 degrees of just horizon" suggests that the ocean rowers are surrounded by water and sky with no land in sight. This implies a feeling of isolation and possibly a lack of direction or motivation to continue. Now, let's evaluate the options: (A) **they are unable to see land in any direction, just sea and sky.** This option aligns with the idea of being surrounded by horizon without any visible land, which could lead to feelings of discouragement. (B) **they need a clear view of the shore to navigate the ocean.** While navigation is important, the statement does not specifically mention the need for a clear view of the shore for navigation. (C) **their view is obstructed by the line where the sea and sky meet.** This option suggests an obstruction, but the phrase "360 degrees of just horizon" indicates a clear view of the horizon, not an obstruction. (D) **their ship to shore communication system might be blocked.** This option introduces a technical issue that is not implied in the original statement. Based on this analysis, the best answer is: **(A) they are unable to see land in any direction, just sea and sky.** This option directly reflects the meaning of being surrounded by horizon and the potential feelings of discouragement that may lead to quitting.