Final answer:
The primary turfgrass used on sports fields in the South and Southwest is Bermudagrass, valued for its durability and ability to withstand heat and drought.
Step-by-step explanation:
The primary turfgrass commonly used on sports fields in the South and Southwest is Bermudagrass (option b). This type of grass is highly favored in these regions due to its resilience to heat and its ability to recover quickly from damage. Bermudagrass has a dense, fine texture and can tolerate close mowing, making it ideal for sports fields where a hard-wearing and a smooth surface is important for playability. Additionally, this grass thrives in full sun and has a great tolerance for drought, which is beneficial in the hot and often dry conditions of the South and Southwest.