Where is the International Maize and Wheat Improvement Center located?

Kufri Pukhraj is a hybrid genetic clone of which of the following?

Fill in the blanks in the following statements ($A$ to $C$):
$(A)$ The capacity to generate a whole plant from any cell/explant is called ......$(i)$ .......
$(B)$ The transfer of resistance genes occurs through ........$(ii)$........ . Subsequently,........$(iii)$ ....... occurs between the target and the plant source.
$(C)$ The rice variety $IR8$ was developed in the country ........$(iv)$ ........

$Sonora-64$ and $Lerma$ $Rojo$ are varieties of:

Discuss the importance of testing of new plant varieties in a geographically vast country like India.

Where was $IR-8$ developed?