Which of the following represents the dimension of a standard plank used in construction?

In construction, a standard plank is typically defined by its nominal dimensions rather than its actual dimensions due to the way wood is milled and finished. A common standard plank size is classified under nominal dimensions, with a true width that is smaller than the nominal measurement.

A plank that measures 3" x 16" is not representative of commonly used dimensions in standard construction practices. The option representing a plank commonly used is more typically around 4 inches in thickness and can range in length, but a dimension of 4" x 16" aligns with commonly accepted lumber sizes, making it a practical choice for structural applications.

While other options may present dimensions that are technically valid, they either fall outside the typical standard sizes in construction or represent other categories of lumber rather than plank sizes. Therefore, the option that correctly represents the dimensions of a standard plank used in construction is the one indicating 4" in width and 16" in length, as this aligns better with industry practices.