Final answer:
The Texas Longhorn was very disease resistant, well adapted to the grasses on the plains, and critical to the Old West's cattle industry. So the correct answer is Option B.
Step-by-step explanation:
The type of cattle that was very disease resistant and well adapted to the types of grasses that grew wild on the plains was the Texas Longhorn. The Longhorn cattle were introduced by the Spanish to the Americas and became synonymous with the Texas frontier. These cattle were remarkable for their ability to thrive on the sparse grasses of the plains and were highly resistant to local diseases such as Texas cattle fever. Despite challenges such as harsh weather conditions and the threat of parasites, the Texas Longhorn was a hardy breed that supported the expansion of the cattle industry in the Old West.