Citrus species, resistant to canker is

Answer: Option A

Citrus species, resistant to canker is Citrus aurantifolia.
Citrus canker is a bacterial disease that causes lesions on the leaves, stems, and fruit of plants including citrus and other plants in the citrus family. While not harmful to humans, the disease affects the health of infected citrus trees and the marketability of infected fruit.
The Key lime or acid lime (C. aurantifolia) is a citrus hybrid (C. hystrix × C. medica) native to tropical Southeast Asia. It has a spherical fruit, 25 - 50 mm (1 - 2 in) in diameter. It is widely used because of its antibacterial, anticancer, antidiabetic, antifungal, anti-hypertensive, anti-inflammation, anti-lipidemia and antioxidant properties.