What is the primary use of oak and hickory trees in Pennsylvania?

The primary use of oak and hickory trees in Pennsylvania encompasses various applications, which is why the correct answer includes all of the options listed. Oak wood is valued for its durability and strength, making it a popular choice for construction materials, such as beams and flooring. Its attractive grain and robust nature also lend themselves well to furniture making, providing both aesthetic appeal and longevity.

Hickory, on the other hand, is known for its exceptional hardness and shock resistance, making it an ideal material for items that require durability. This includes baseball bats, which benefit from hickory's ability to withstand impact, as well as quality flooring that demands both strength and a beautiful finish.

Together, oak and hickory serve multiple industries and purposes in Pennsylvania, from construction to crafting high-quality furniture and sporting goods. Thus, recognizing the breadth of their applications affirms that "all of the above" is the most accurate representation of their primary uses.