What type of AM layer construction method involves creating lines of material with a single-point source?

The method that involves creating lines of material with a single-point source is correctly identified as 1D channel. This technique focuses on the sequential deposition of material in a one-dimensional manner, where the deposition occurs along a defined path resulting in narrow lines or strands. This approach is often used in processes like Fused Deposition Modeling (FDM) where a filament is heated and extruded to create these linear structures.

In contrast, other methods listed do not exclusively focus on this single-point and linear approach. For instance, two-dimensional (2D) channel methods typically involve a broader area of deposition, while layered deposition implies building up layers rather than focusing strictly on the linear application. Multi-point source construction utilizes multiple points to deposit material simultaneously, diverging from the concept of a singular, focused deposition line. Thus, the correct choice emphasizes the specificity and technique of using a single-point source to create material lines in a controlled, linear fashion.