The $RNA$i stands for

$A$ : Some nations are developing laws to prevent unauthorised exploiation of their bioresources and traditional knowledge.
$R$ : Brazzein, a protein obtained from West African plant, was isolated, sequenced and patented in $U.S.A.$

Which one of the following is commonly used in transfer of foreign $DNA$ into crop plants?

Saccharomycetes cerevisae is

Bt cotton is not