Gravitational potential energy (Ug) is calculated using the formula Ug = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height. Since the mass of the seed and

Gravitational potential energy ($U_g$) is calculated using the formula $U_g = mgh$, where $m$ is the mass, $g$ is the acceleration due to gravity, and $h$ is the height. Since the mass of the seed and the acceleration due to gravity are constant, the gravitational potential energy is directly proportional to the height. To have the least gravitational potential energy, the seed must be at the lowest possible height.

• When the seed was attached to the tall branch, it was at its highest point.
• When the seed was blown off the branch, it was falling, so its height was decreasing but not yet at its lowest.
• When the seed was about to germinate in the dirt, it had landed on the ground and was in the dirt, representing its lowest height.

Therefore, the least gravitational potential energy occurred when the seed was at its lowest point.

The correct option is:

• when the seed was about to germinate in the dirt