Agrobacterium tumifaciens, is able to deliver a piece of DNA known as _____________ to transform normal plant cell into a tumor cell.

T-DNA

The correct answer is Option (1) - T-DNA

Agrobacterium tumefaciens is a bacterium commonly used as a tool in plant genetic engineering. It can transfer a specific segment of DNA (T-DNA) into the plant genome. Researchers have used this system to introduce nematode-specific genes into plants to confer resistance against nematode pests. This technique allows the plant to produce substances that interfere with the nematode's ability to infect or damage the plant.