Which one of the following is not used in the production of yoghurt

Branch dealing with genetic engineering is

Read the following four statements $(A-­D)$ about certain mistakes in two of them.

$(A)$ The first transgenic buffalo, Rosie produced milk which was human alpha­ lactalbumin enriched.

$(B)$ Restriction enzymes are used in isolation of $DNA$ from other macromolecules.

$(C) $ Downstream processing is one of the steps of $rDNA$ technology.

$(D)$ Disarmed pathogen vectors are also used in transfer of $rDNA$ into the host.

Which of the two statements have mistakes ?

The vector for $T-DNA$ is

Polypeptide chain present in insulin are Linked together by..