Which strand of DNA allows DNA polymerase and helicase to work in the opposite direction?

The lagging strand is the correct choice because it is synthesized discontinuously in short segments, known as Okazaki fragments, as the DNA unwinds. DNA polymerase synthesizes new DNA in a 5' to 3' direction, but as the replication fork opens up, the lagging strand is oriented in a way that requires DNA polymerase to work away from the fork. This necessitates multiple initiation events and the activity of helicase to unwind the DNA ahead of polymerase.

In contrast, the leading strand is synthesized continuously in the same direction as the movement of the replication fork, allowing for a smoother and more straightforward process. The term "antiparallel strand" refers to the arrangement of the two strands of DNA, which run in opposite directions, but it doesn't specifically address the directionality of replication. The complementary strand is simply a reference to the base pairing rule, where each base on one strand pairs with a specific base on the opposite strand, but this does not relate to the activity of the enzymes during replication. Thus, the unique characteristics of the lagging strand enable DNA polymerase and helicase to function oppositely in the context of DNA replication.