Sonora-64 and Lerma Rojo-64 were brought to India from Mexico and modified through

The correct option is B $\gamma$- rays

A. UV rays or ultraviolet rays are the electromagnetic radiations that have wavelength range 200-400 nm.

B. X rays are the electromagnetic radiations having low wavelength range of about 0.01-10 nm.

C. β rays are high energy radiations emitted during radioactive decay of atomic nucleus when it undergoes beta decay.

D. γ rays are low wavelength electromagnetic radiations emitted during radioactive decay of nucleus. These rays are used to induce mutations in the crops to form new varieties.

Sonora-64 and Lerma Rojo-64 are dwarf wheat varieties which were developed in Mexico and modified through γ rays. These are highly productive varieties and were introduced into India to meet the increasing demands of food consumption.

So, the correct answer is 'γ-rays'.