Which type of tropism is seen during growth of pollen tube towards ovule ?

Chemotropism 

The correct answer is Option (3) – Chemotropism
Chemotropism is the growth of organisms such as bacteria and plants, with the help of a chemical stimulus from outside of the organism or from the organism's part.

The response of the organism is termed 'positive' if the growth is towards the stimulus or 'negative' if the growth is away from the stimulus.

An example of chemotropic movement can be seen during the growth of the pollen tube, where growth is always towards the ovules. 

The chemo- means relating to chemicals and tropism means chemotropism. Chemotropism is the growth of organisms by chemical stimuli from outside of the organism. It is mostly seen in bacteria, plants, and fungi.