Final answer:
Sod installed in the northern U.S. typically involves cool-season grasses such as Kentucky bluegrass, perennial ryegrass, and fescues, due to their suitability for the climate.
Step-by-step explanation:
When sod is installed in the northern United States, it is probably a species of cool-season grass, given that these species are well-suited to the colder climates found in this region. The most common types of turfgrass used for sod in these areas include Kentucky bluegrass, perennial ryegrass, and fescues. These grasses are favored for their ability to thrive in the cooler temperatures and their resilience to the changing seasons, providing a lush, green lawn throughout much of the year.