Which cable is more flexible but not as strong?

The most flexible cable among the given options is the 8x19 cable. This designation refers to the construction of the wire rope, where "8" indicates the number of strands, and "19" indicates the number of wires in each strand. With more wires distributed across the strands, the 8x19 cable allows for greater bending and flexibility compared to the other options with fewer wires.

This flexibility is particularly advantageous in applications where the cable needs to navigate through tight spaces or endure frequent movement. However, this increased flexibility often means that such cables may not have the same tensile strength as those constructed with fewer strands or fewer wires per strand. Generally, cables with a lower number of wires per strand (like the 6x19 or 5x19 cables) tend to offer higher strength due to the larger diameter of each wire, but they can be less flexible as a result.

In summary, the specific construction of the 8x19 cable makes it the correct choice for the question regarding greater flexibility but comparatively lower strength, thereby fulfilling the criteria set forth.