In a china-rose (Hibiscus or gudhal) plant, a pollen tube grows and continues through the style after pollen lands on the stigma. Which process is about to happen next? [Pg. No. 217]

After the pollen tube grows through the style and reaches the ovary, the male gamete (from the pollen) joins with the female gamete (the egg present in the ovule). This fusion of the male and female gametes is called fertilisation, and it produces a zygote.
In short: pollination → pollen tube grows through style → fertilisation (male gamete fuses with egg) → zygote forms → seed and fruit develop.