​The long DNA strand depicted below is serving as a template for lagging strand DNA synthesis. The short lines represent the newly synthesized Okazaki fragments.​

​At which positions among A, B, C, and D would DNA primase act next?​

Correct option is D

Explanation-

Lagging strand is synthesized discontinuously in short stretches (Okazaki fragments). New Okazaki fragments are made in the 5′ → 3′ direction, but overall synthesis moves away from the replication fork.DNA primase synthesizes an RNA primer to start each Okazaki fragment. The next primer will be laid closer to the replication fork, i.e., further along the 3′ end of the template strand.
Template Strand Direction:
Given strand:
5′ —————————————————————————— 3′
So, replication (Okazaki fragments) happens from right to left, growing toward the 5′ end. But the replication fork is on the right (3′) end, moving rightward.
Thus, new Okazaki fragments are initiated toward the right.

The existing Okazaki fragments are already placed at positions A, B, and C.
Position D is the next open spot in the 5′ → 3′ template strand, closer to the replication fork than the others.

DNA primase lays the next primer at D, since it is:
                                                  1.   Closest to the replication fork.
                                                  2.   The site where the next Okazaki fragment will begin.