Methods of producing microbe and pest resistant plants include

$A$: Production of hirudin from transgenic $Brassica$ required the use of a synthetic gene.
$R$: Eukaryotic genes have intron sequences that need to be spliced out.

$Bt$ cotton is resistant to pests,such as lepidopterans,dipterans,and coleopterans. Is $Bt$ cotton also resistant to other pests as well?

Select the appropriate option for organisms used in biotechnology.

Choose the correct option regarding the organism that infects the roots of tobacco plants.

Given below are $2$ statements: one is labelled as Assertion $(A)$ and other is labelled as Reason $(R)$.
Assertion $(A) :-$ Toxic insecticidal protein of Bacillus thuringiensis does not kill Bacillus itself.
Reason $(R) :-$ In Bacillus,$Bt$ toxin protein exists as inactive protoxins.
Correct answer from the options given below :