Final answer:
The second oldest upper motor neuron pathway is involved in voluntary movement and skilled motor tasks.
Step-by-step explanation:
The role of the second oldest upper motor neuron (UMN) pathway is a. Voluntary movement and skilled motor tasks.
Upper motor neurons are responsible for relaying signals from the primary motor cortex to the lower motor neurons, which then activate the skeletal muscles in the body. The second oldest UMN pathway, called the corticospinal tract, controls conscious or voluntary movements of skeletal muscles. It enables us to perform skilled motor tasks and execute voluntary movements such as walking, writing, or playing an instrument.
Overall, the role of the second oldest UMN pathway is to facilitate voluntary movement and skilled motor tasks.