Which of the following terms is used to describe cracks that develop along the growth rings in lumber?

The correct term for cracks that develop along the growth rings in lumber is "checks." These are small fissures that occur due to seasonal changes and drying processes in the wood. As lumber dries, the outer areas may shrink, leading to the development of these cracks primarily along the growth rings as they have a tendency to remain intact while the rest of the wood shrinks.

Knots are imperfections in wood caused by the presence of branches that were once attached to the tree, not related to growth rings. Splits refer to more severe cracks that can run across the grain of the wood, often resulting from excessive stress or improper handling, which is different from the localized nature of checks. Shakes are similar to checks but typically occur along the grain and are related to the way the wood was formed or influenced by environmental factors during the growth of the tree.

Thus, understanding the characteristic features and formation processes of these defects helps clarify why "checks" is the appropriate term for the cracks resulting from the shrinkage along the growth rings.