Plant disease, Citrus Canker, is caused by:

Correct option is B

Citrus canker is caused by the bacterium Xanthomonas campestris pv citri, which leads to lesions on leaves, stems, and fruits.
Symptoms:
· Affects acid lime, lemon, and grapefruit; rare on sweet oranges and mandarins.
· Targets leaves, twigs, and fruits; leaves are not distorted.
· Circular lesions with a yellow halo appear on both sides of the leaf, severe in acid lime.
· Lesions on twigs cause girdling and dieback.
· Reduces market value when lesions appear on fruits.
Management:
· Use Streptomycin sulphate (500-1000 ppm), Phytomycin (2500 ppm), or Copper oxychloride (0.2%) at fortnightly intervals.
· Control leaf miner during young flush growth.
· Prune severely infected twigs before the monsoon.