To solve this problem, we need to identify the incorrect statement regarding post-fertilization development in flowering plants. Let's analyze each option:$\newline \bullet$Option 1: Ovary develops into fruit.$\newline$ - After fertilization, the ovary of a flower develops into a fruit. This is a correct statement.$\newline \bullet$Option 2: Zygote develops into embryo.$\newline$ - The zygote, formed by the fusion of male and female gametes, develops into an embryo. This is a correct statement.$\newline \bullet$Option 3: Central cell develops into endosperm.$\newline$ - The central cell, after fertilization, develops into the endosperm, which provides nourishment to the developing embryo. This is a correct statement.$\newline \bullet$Option 4: Ovules develop into embryo sac.$\newline$ - This statement is incorrect. The ovules develop into seeds, not embryo sacs. The embryo sac is the female gametophyte present within the ovule before fertilization.$\newline$Therefore, the incorrect statement is Option 4: Ovules develop into embryo sac.