Solution

The correct answer is A - III, B - IV, C - II, D - I

Key Points

• 10.20.30.40 (A):
  • This IP address falls within the range of 1.0.0.0 to 126.0.0.0, which is designated for Class A. So, A matches with III.
• 210.20.30.3 (B):
  • This IP address falls within the range of 192.0.1.0 to 223.255.254.0, which is designated for Class C. So, B matches with IV.
• 180.30.100.10 (C):
  • This IP address falls within the range of 128.1.0.0 to 191.255.0.0, which is designated for Class B. So, C matches with II.
• 252.5.15.11 (D):
  • This IP address falls within the range of 240.0.0.0 to 255.255.255.255, which is designated for Class E. So, D matches with I.

Therefore, the correct option is A - III, B - IV, C - II, D - I. So, the correct option is 4).