C) Artificial hybridization because it enables crossing of different species and often different genera to combine desirable characters to produce commercially superior varities.

The major approach towards the crop improvement programme is Artificial hybridization.

Explanation:
Artificial hybridization is a major approach used in crop improvement programmes. It involves the deliberate crossing of two different varieties or species of plants with desirable traits to produce offspring with improved characteristics. This process is carried out by plant breeders to create new varieties of crops that have better yield, resistance to diseases and pests, improved quality, and other desirable traits.

Steps involved in artificial hybridization:
1. Emasculation: This is the removal of the male reproductive organs (anthers) of a flower before they release pollen. Emasculation is done to prevent self-pollination and to ensure controlled cross-pollination with the desired male parent.

2. Bagging: After emasculation, the emasculated flower is covered with a bag to prevent unwanted pollination from other sources. This ensures that only the desired pollen from the selected male parent is used for fertilization.

3. Pollen transfer: The bagged flower is then pollinated with the pollen from the male parent. This can be done by manually transferring the pollen onto the stigma of the emasculated flower.

4. Fertilization: After pollination, the pollen grains germinate on the stigma and the pollen tube grows down to the ovary. The male gametes (sperm cells) then fertilize the female gametes (egg cells) in the ovule, leading to the formation of seeds.

5. Seed development: The fertilized ovules develop into seeds, which inherit traits from both the male and female parents. These seeds are collected and grown to produce the next generation of plants.

6. Selection and breeding: The offspring from the artificial hybridization process are evaluated for their desirable traits. The best plants with the desired characteristics are selected as parents for the next generation, and the process is repeated to further improve the crop.

Artificial hybridization allows plant breeders to combine the best traits from different varieties or species, leading to the development of new crop varieties with improved characteristics. This approach has been widely used in crop improvement programmes to enhance agricultural productivity and meet the growing demands for food.