Cоuchоux et аl. (2018) studied effects оf pаrаsites on the reproduction of their hosts of Gammarus roeseli, a freshwater amphipod (Crustecean). In particular, they studied strategic sperm investment of males to uninfected females or to those who were infected with one of two microsporidian parasites (N. granulosis or Dictyocoela sp) (a) Is this a proximate or ultimate question? Why? (b) Based on the figure below, what conclusions can the researchers make? Refer to the figure in your answer.