A restorer gene is present in

Answer: Option A

A restorer gene is present in Nucleus.
The restorer line is used to restore the fertility in the hybrid after crossing with the ms A line in the hybrid production plot.
Fertility restorer (Rf) genes block or compensate for specific mitochondrial dysfunctions that are phenotypically expressed during pollen development.
Different Rf genes have been identified and mapped on different chromosomes along with their molecular mechanisms in restoring fertility.