The correct answer is (c), tobacco.
The first transgenic plant was tobacco, which was genetically modified in 1983 by inserting a gene from the bacterium Bacillus thuringiensis (Bt) that produces a protein toxic to insects. This was a major breakthrough in the field of genetic engineering, and it paved the way for the development of many other transgenic crops.
Pea, flax, and cotton are all important crops that have been genetically modified, but they were not the first transgenic plants. Tobacco was chosen for the first genetic engineering experiments because it is a relatively easy plant to grow and manipulate in the laboratory. It is also a relatively small plant, which makes it easier to handle and study.
The Bt gene that was inserted into the tobacco plant produces a protein called Cry1Ac. This protein is toxic to insects that feed on the plant, such as the tobacco budworm and the Colorado potato beetle. When these insects eat the transgenic tobacco plant, they die.
The development of transgenic tobacco plants has had a major impact on agriculture. These plants are now widely used to control insect pests, and they have helped to reduce the use of chemical pesticides. Transgenic tobacco plants have also been used to produce other valuable products, such as pharmaceuticals and biofuels.