To determine the position of the Sun, Earth, and Moon during a full moon, we need to look for the arrangement where the Earth is positioned between the Sun and the Moon.
During a full moon, the Moon is on the opposite side of the Earth from the Sun, meaning that when you look up at the Moon during a full moon, the Sun is shining directly on the Moon, illuminating it fully.
So, if the diagrams show the positions of the Sun, Earth, and Moon, look for the one where the Sun (A) is on one side, the Earth (B) is in the middle, and the Moon (C) is on the opposite side of the Earth from the Sun.
If you have specific diagrams to refer to, please describe them so I can assist you in identifying the correct one.