Correct Answer: 80 - 93

Solution : Two numbers are said to be co-prime if there is no number other than 1 that divides both numbers.

Let's check the options —

First option: 14 - 16; Both 14 and 16 are divisible by 1 and 2. So, they are not co-prime.

Second option: 56 - 64; Both 56 and 64 are divisible by 1, 2, 4, and 8. So, they are not co-prime.

Third option: 77 - 88; Both 77 and 88 are divisible by 1 and 11. So, they are not co-prime.

Fourth option: 80 - 93; Both 80 and 93 are divisible by only 1. There is no other number that divides both these numbers. So, they are co-prime. This option is different from the other options.

Hence, the fourth option is correct.