The botanical name of the National flower of India is

The botanical name of Indian National flower is Nelumbo nucifera. Nelumbo nucifera, also known as Indian lotus, sacred lotus, bean of India or simply lotus is one of two species of aquatic plant in the family Nelumbonaceae. The roots of the lotus are planted in the soil of the pond or river bottom, while the leaves float on top of the water surface or are held well above it. Flowers are generally attached to the thick stem.

Hence, the correct option is B.