The correct option is C 58 and 15
For plant grafting, the roots from one plant called the stock is taken and joined to either stem, leaves, fruit etc. of another plant. The upper part attached to the stock is called the scion. since the scion will give rise to the appendages like flower, fruit etc. the chromosome number in the vegetative parts of the scion will be same as the original i.e. 30. However, in gamates; egg cell or pollen the chromosome number will be half of the original plant (in this case scion) so, it will be 15. Since the stock forms the root system the chromosome number remains unchanged in those cells. Thus, the correct option is C.