**Core Concept**
Copper-T intrauterine devices (IUDs) are a type of non-hormonal, long-acting reversible contraceptive method. The timing of IUD insertion postpartum is critical to minimize the risk of complications, such as uterine perforation and infection.

**Why the Correct Answer is Right**
Insertion of the Copper-T IUD is preferably delayed until 8 weeks postpartum to allow for the resolution of postpartum hemorrhage, uterine involution, and the return of the uterine tone to normal. This timing also minimizes the risk of uterine perforation and reduces the likelihood of expulsion. Additionally, the copper ions released from the IUD may interfere with lactation and breast milk production, making delayed insertion preferable.

**Why Each Wrong Option is Incorrect**
**Option A:** Insertion at 2 weeks postpartum may be too early, as the uterus is still involuting and the risk of uterine perforation is higher.
**Option B:** Insertion at 4 weeks may still be too early, as the uterus may not have fully returned to its pre-pregnancy size and tone.
**Option C:** Insertion at 5 weeks is not significantly different from 4 weeks in terms of uterine involution and tone.

**Clinical Pearl / High-Yield Fact**
It is essential to delay IUD insertion postpartum until the uterus has fully involuted and returned to its pre-pregnancy size and tone to minimize the risk of complications.

**✓ Correct Answer: D. 8 weeks**