Why are the phases of the Moon considered a predictable pattern?

Because the Moon's brightness changes based on solar flares.

Because the Earth's rotation on its axis is perfectly stable.

Because the Moon follows a stable and consistent orbit around the Earth.

Because the distance between the Earth and Sun varies throughout the year.

What is the fundamental reason that the Moon's phases occur in a repeating cycle rather than a random order?

The Moon's synchronous rotation

Waxing Crescent → Quarter Moon → Waxing Gibbous

Full Moon → Waning Gibbous → Third Quarter

Full Moon → Quarter Moon → Waxing Crescent

Quarter Moon → Waxing Gibbous → Full Moon

The cycle could have started from any phase.