A transgenic food crop which may help in solving the problem of night blindness in developing countries is

Main objective of production/use of herbicide resistant $GM$ crops is to
$(A)$ -Reduce herbicide accumulation in food articles for health safety.
$(B)$ -Eliminate weeds in the field without the use of herbicides
$(C)$ -Eliminate weeds from the field without the use of manual labour.
$(D)$ -Soil pollution and biomagnification caused by herbicides.
Which of the following statements are correct?

Bt toxin kills the insect by

Waksman got Nobel Prize for the discovery of