What material's weight can help secure the line during masonry work?

Brick is the correct choice because it is a heavy material that can be used effectively to help secure a line during masonry work. In masonry, a line is often stretched between two points to guide the alignment of bricks or blocks being laid. The weight of the brick can help to keep the line taut and stable, ensuring that the masonry work remains straight and level. This is particularly important for achieving accurate spacing and alignment in the structure being built.

Other materials, while they may have their uses in construction, do not offer the same combination of weight and stability as brick when it comes to securing a line. Wood, although it can be heavy, is typically not used in this context since it is less stable and may bend or warp over time. Plastic is generally too lightweight and lacks the necessary heft to maintain tension in a line effectively. Metal could be heavy enough, but it may not be practical or common in masonry applications where bricks are the standard material for securing lines during construction.