**Core Concept**
Okazaki segments are short, discontinuous DNA fragments synthesized in the lagging strand during DNA replication. They are crucial for the process of replication in prokaryotes and eukaryotes, ensuring the unwinding of the double helix and the synthesis of new DNA strands.

**Why the Correct Answer is Right**
The lagging strand is synthesized discontinuously due to the antiparallel nature of DNA strands. As the replication fork moves forward, the leading strand is synthesized continuously, but the lagging strand is synthesized in short, discontinuous segments called Okazaki fragments. This allows for the unwinding of the double helix and the synthesis of new DNA strands. The Okazaki fragments are then joined together by DNA ligase to form a continuous strand.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Okazaki segments are not required for the leading strand, which is synthesized continuously.
* **Option B:** This option is incorrect because Okazaki segments are not specific to prokaryotes; they are also found in eukaryotes.
* **Option C:** This option is incorrect because Okazaki segments are not a type of DNA repair mechanism; they are a feature of DNA replication.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Okazaki segments are synthesized in the direction 5' to 3' on the lagging strand, which is opposite to the direction of DNA synthesis on the leading strand.

**Correct Answer:** D.