The correct option is
C Gulmohar
Gulmohar belongs to the family Leguminosae. It shows the papilionaceous type of the corolla that has unequal size of the petals. So, the flower cannot be divided into two equal halves in any plane. There is only one plane of division. Such flowers show the irregular symmetry and are called zygomorphic. When the floral parts are of the same size, their division is possible along any plane. Such flowers are regular flowers and are called actinomorphic.
Hence, the correct answer is 'Gulmohar'