Answer:
D. X: Gene for sweeter fruit
Y: Apple tree DNA
Step-by-step explanation:
The process that producing apple trees with desired trait of sweeyer fruits will require gene for sweeter fruit and apple tree DNA.
Genes are responsible for carrying traits or characterstics from parent to daughter, here the trait is sweetness and genes are must to carry this trait otherwise apple will lack sweetness.
DNA carry instructions which are required to develop, reproduce and survive by an organism. DNA undergoes several processes like replication, transcription and translation and share the DNA of male and female parent (sexual reproduction) to produce new organism or plant. hence, DNA of apple tree will be required.
Hence, the correct option is D.