Who among the following was primarily an exponent of Bharatanatyam dance?

Rukmini Devi Arundale was an iconic Indian classical dancer and choreographer who led the renaissance of Bharatanatyam dance from its traditional sadir format and helped save it from extinction. She was also the first woman in Indian history to be nominated as a member of the Rajya Sabha.
Let's look at the other classical dance exponents given in options:

* Kelucharan Mohapatra $\to$ Odissi
* Guru Bipin Singh $\to$ Manipuri
* Pandit Birju Maharaj $\to$ Kathak