Option 1 states that 1 nm is equal to 10-1 A. This is incorrect because the prefix "n" represents a factor of 10-9, not 10-1. Therefore, this option is incorrect.

Option 2 states that 1 nm is equal to 10 A. This is the correct answer. The prefix "n" represents a factor of 10-9, and the prefix "A" represents a factor of 10. When multiplied together, 10-9 * 10 = 10-8, which simplifies to 10 A.

Option 3 states that 1 nm is equal to 1 A. This is incorrect because the prefix "n" represents a factor of 10-9, not 1. Therefore, this option is incorrect.

Option 4 states that 1 nm is equal to 10-2 A. This is incorrect because the prefix "n" represents a factor of 10-9, not 10-2. Therefore, this option is incorrect.

In summary, the correct relation between A and nm is option 2, which states that 1 nm is equal to 10 A.