The correct option is
B (i) - (e), (ii) - (d), (iii) - (a), (iv) - (b)
Diplococcus pneumoniae is the gram-positive bacterium causing pneumonia in mice and humans. Citrus canker is a disease affecting citrus species caused by the bacterium
Xanthomonas citri. Infection causes lesions on the leaves, stems, and fruit of citrus trees, including lime, oranges, and grapefruit.
Vibrio cholerae is a gram-negative, comma-shaped bacterium that cause the disease cholera. Leprosy is a chronic infection caused by the acid-fast, rod-shaped bacillus
Mycobacterium leprae.
Therefore, the correct answer is option B.