Which tool is most widely used in the genetic engineering of crop plants?

Which of the following is true for Golden rice?

$Bacillus \text{ } thuringiensis$ \text{ } \text{bacteria contain } Bt \text{ } \text{toxin protein crystals. These do not kill the bacteria themselves because:}

In $RNA$ interference,the $dsRNA$ molecule prevents . . . . . . .

Given below are two statements:
Statement $I$: $Bt$ toxins are insect group specific and coded by a gene $cry$ $IAc$.
Statement $II$: $Bt$ toxin exists as inactive protoxin in $B. \text{ thuringiensis}$. However, after ingestion by the insect, the inactive protoxin gets converted into active form due to alkaline $pH$ of the insect gut.
In the light of the above statements, choose the correct answer from the options given below:

Golden rice is enriched with which of the following?