Read the following four statements $(A-D)$ and identify the mistakes in two of them.
$(A)$ The first transgenic cow,Rosie,produced milk which was human alpha-lactalbumin enriched.
$(B)$ Restriction enzymes are used in the 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 the transfer of $rDNA$ into the host.
Which of the two statements have mistakes?

• A
  $B$ and $C$
• B
  $C$ and $D$
• C
  $A$ and $C$
• D
  $A$ and $B$