Trimethoprim-sulfamethoxazole (SXT) disks are used with bacitracin disks to differentiate which streptococci

The correct answer is - β-Hemolytic streptococci.

Explanation:

Beta hemolytic or complete hemolysis termed on the characteristic of the complete lysis of red cells due to the enzyme streptolysin, under the colonies. These are leads to the particular area to be transparent and lightened.

Beta hemolytic streptococci are one type of beta-hemolytic bacteria that are fall in group A streptococci, these bacteria produce an exotoxin enzyme. Bacitracin with trimethoprim-sulfamethoxazole disks is used to differentiate these streptococci.

Thus, the correct answer is - β-Hemolytic streptococci.