Step 1: The task.
We sort four birth control items into their correct categories.
Step 2: Vasectomy.
In a vasectomy the vas deferens in the male is cut and tied by an operation. That makes it a surgical method. So A goes with III.
Step 3: Coitus interruptus.
This is simply withdrawal before ejaculation, using no device or drug. It is a natural method. So B goes with IV.
Step 4: Cervical caps.
Cervical caps physically cover the cervix and block sperm from entering. That makes them a barrier method. So C goes with II.
Step 5: Saheli.
Saheli is a non-steroidal pill taken by mouth once a week. It is an oral method. So D goes with I.
Step 6: Conclusion.
The match is A-III, B-IV, C-II, D-I, so the answer is "A-III, B-IV, C-II, D-I". \[ \boxed{\text{A-III, B-IV, C-II, D-I}} \]