What best describes a standard blood drop from a 90-degree angle?

When blood is dropped from a height at a 90-degree angle, gravity pulls it straight down, causing the droplet to form a perfect circle upon impact with a surface. This circular shape occurs because the force of the falling blood creates equal tension in all directions upon contact, resulting in a uniform, rounded appearance.

In contrast, when blood drops at angles other than 90 degrees, it can create elongated shapes or splatters due to the angle’s influence on how the droplet disperses on impact. A significant spread or splatter pattern typically occurs with higher velocity impacts or with angles that are not perpendicular. Meanwhile, a long streak would generally suggest a dragging motion rather than a direct drop. Therefore, the description of the blood drop being circular when dropped from a 90-degree angle is the most accurate representation of its behavior upon impact.