Axis developing between androecium and gynoecium is

The development of internode between the androecium and the gynoecium and raise the gynoecium above the general level of the flower is called as gynophore. It is the stalk of flowers which supports the gynoecium elevating it above the branching points of other floral parts. For example, Michelia, Capparis, Gynandropsis in which there is a green rod-like structure found between androecium and gynoecium. 
Therefore, the correct answer is option C.