Answer:
b. The herbicide-resistance gene is cloned into the T-DNA region of the Ti-plasmid.
Step-by-step explanation:
Ti-plasmid has the ability to introduce part of its DNA (t-DNA) into the genome of host plants. This is very important for the relationship of genetic manipulation in maize plants, with the aim of inducing a gene that promotes herbicide resistance. In addition, T-DNA has many genes that code for the production of plant growth phytohormones, which is extremely important for the cloning process to work. In this case, we can assume that the correct answer for yours is the letter B.