The correct answer is: C. 120 meters.
MACLS stands for Multiple Access with Carrier and Timing Synchronization. It is a technique used in LTE to allow multiple users to share the same frequency band without interfering with each other. MACLS works by dividing the frequency band into smaller blocks, and then assigning each user a different block. The blocks are then transmitted in a staggered fashion, so that each user only receives the blocks that are assigned to them.
In order for MACLS to work properly, it is important that the blocks overlap at the receiver. This overlap allows the receiver to synchronize the timing of the different blocks, and to decode the data that is being transmitted. The amount of overlap that is required depends on the specific implementation of MACLS, but it is typically in the range of 120 to 240 meters.
Option A is incorrect because it is the maximum amount of block overlap that is allowed in LTE. Option B is incorrect because it is the minimum amount of block overlap that is required for some implementations of MACLS. Option D is incorrect because it is not possible to have zero block overlap.