Root nodules for nitrogen fixation in non-leguminous trees are produced by species of the genus

Which one of the following can utilize molecular nitrogen $(N_2)$ as a nutrient for growth?

The $hup$ gene is found in .........

Bacteria found in root nodules of legumes are

Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation?

Select the correct statements from the given:
$(a)$ Nitrogenase is a heterodimeric protein.
$(b)$ Root hairs curl by action of nitrogenase and plant 'nod factors'.
$(c)$ During symbiotic $N_2$ fixation,$ATP$ is provided by the legume plant.