Match the tool of rDNA technology with its primary function.
| Column I | Column II |
|---|---|
| (a) Restriction enzyme | (i) An agent to carry foreign DNA into a host cell |
| (b) DNA Ligase | (ii) Used to separate DNA fragments by size |
| (c) Vector | (iii) Makes cuts at specific positions within the DNA |
| (d) Gel Electrophoresis | (iv) Joins DNA fragments by forming phosphodiester bonds |