Transposons can be used during which one of the following?

Give scientific reasons : $Bt$ protein can not kill Bacillus.

Golden rice

$I$. It is a transgenic variety of rice

$II$. It contains a goods quality of $\beta$-carotene (provitamin-A)

$III$. $\beta$-carotene is a principal source of vitamin- $A$

$IV$. The grains of the rice are yellow in colour due to $\beta$-carotene. The rice is commonly called golden rice

Which of the statements given above are correct?

Genetic engineering is the