The correct answer is B) toms. Securing cargo by running timbers from an upper support down to the cargo, either vertically or at an angle, is called toms. Toms are a type of cargo securing device used to prevent the cargo from shifting during transport. They are typically made of wood or metal and are wedged or secured in place to provide additional support and stability for the cargo. The other options are incorrect because: A) Braces are structures that provide lateral support, not the vertical or angled supports described in the question. C) Dunnage refers to the material placed under and around cargo to prevent damage, not the securing devices themselves. D) Shores are vertical supports placed against the sides of cargo to prevent movement, not the diagonal supports described.