Final answer:
b) number and spacing of the spreades. The visual clue that can help discriminate between tie rods and anchor plates is the number and spacing of the spreaders.
Step-by-step explanation:
The visual clue that can help discriminate between tie rods and anchor plates is the number and spacing of the spreaders. Tie rods are used to hold structural members together and do not typically need a wide spreader whereas anchor plates, which are used to anchor structures to the ground, often require wider spreaders. By examining the number and spacing of the spreaders, you can determine whether you are looking at a tie rod or an anchor plate.