Option 1 -> Incorrect, this would mean the Moon's gravity is half of Earth's, which is too high.
Option 2 -> Incorrect, this would mean the Moon's gravity is one-third of Earth's, which is still too high.
Option 3 -> Correct, the Moon's gravity is approximately 1.6 m/s² compared to Earth's 9.8 m/s², giving a ratio of about 1/6.
Option 4 -> Incorrect, this underestimates the Moon's gravity; it's not quite that weak.
Hence, Option 3: 1/6 -> The Moon's mass is about 1/81st of Earth's mass and its radius is about 1/3.7 of Earth's radius, which results in surface gravity being approximately 1/6th of Earth's surface gravity -> correct