Option- 1: 321 km - This option implies that 1° of latitude is equal to 321 km. This is not correct as 1° of latitude is not that large of a distance.

Option- 2: 211 km - This option suggests that 1° of latitude represents 211 km. While this is closer to the correct answer, it is not the exact value.

Option- 3: 111 km - This is the correct answer. 1° of latitude is approximately equal to 111 km. It is important to note that this value may vary slightly depending on the exact location on Earth.

Option- 4: 91 km - This option states that 1° of latitude is equivalent to 91 km. This is not accurate as the actual value is slightly larger.

The correct answer to the question is option- 3, which correctly represents that 1° of latitude is approximately equal to 111 km.