The Difference Between MDR-TB and XDR-TB Is That

The difference between MDR-TB and XDR-TB is that

A) XDR-TB is predominantly seen in the USA whereas MDR-TB is common in India and China.
B) MDR-TB exhibits resistance to isoniazid and rifampin whereas XDR-TB strains are resistant to bedaquiline.
C) MDR-TB strains have a higher mortality rate than XDR-TB strains.
D) MDR-TB strains are classified as having resistance to two antibiotics, whereas XDR-TB strains are classified when they are resistant to four antibiotics.