SUBTRACT 2 from first digit and subtract 1 from second digit and then MULTIPLY the digits.6 × 4 = 12; 4 × 3 = 127 × 5 = 20; 5 × 4 = 205 × 8 = 21; 3 × 7 = 215 × 7 = ; 3 × 6 = 18Hence, OPTION 2 is the correct answer.