The key tools of recombinant DNA technology are:

(A) Ligases
(B) Restriction enzymes
(C) Polymerase enzymes
(D) Suitable vectors and host organisms

Choose the correct answer from the options given below:

(A), (B), (C) and (D)

The correct answer is Option (3) → (A), (B), (C) and (D) 

• B. Restriction enzymes: Restriction enzymes are used to cut DNA at specific sequences.
• A. Ligase: Ligases are enzymes that join DNA fragments together.
• C. Polymerase enzyme: Polymerase enzymes are used for amplifying DNA sequences (e.g., through PCR) and are essential in recombinant DNA technology.
• D.Suitable vectors and host organisms : Vectors are DNA molecules used to carry foreign genetic material into a host cell and host organisms are necessary for cloning and expression of recombinant DNA.