Match the term to its significance in biotechnology.
| Column I | Column II |
|---|---|
| (a) Nematode-specific genes | (i) Introduced into host plants to create resistance |
| (b) Ti plasmid | (ii) Used as a vector to deliver genes into plants |
| (c) Retrovirus | (iii) Used as a vector to deliver genes into animals |
| (d) Agrobacterium | (iv) The source of the Ti plasmid |