Concept:The second number is obtained by cubing the first number and adding 1.Explanation:Given: 3−2833+1=27+1=28Given: 9−73093+1=729+1=730So the rule is x→x3+1.Check the options:Option 1: 8−645 → 83+1=512+1=513î€ =645Option 2: 5−124 → 53+1=125+1=126î€ =124Option 3: 7−342 → 73+1=343+1=344î€ =342Option 4: 1−2 → 13+1=1+1=2Only option 4 satisfies the given relation.Answer:Option 4: 1−2