Over time, marine mollasks called nautiloids continually add segments to their shells, and the chemical composition of each segment is influenced by the available materials in the surrounding water when the segment forms. . Paleontologist Amane Tajika and colleagues analyzed the septa (the walls between shell chambers) of one male (samples Jabeled "M") and one female (samples labeled "F"nautiloid, finding that sample FO4 had the same concentration of c oxygen-18 as did water approximately 90 meters deep and that the oxygen-18 concentration in sample MER matched that of water at approximately 385 meters deep. Tajika et al. concluded that sample FO4 formed at a higher point in the water column than did M17 Which finding, if true, would most directly support the researchers conclusions? A) In nautiloids, sex predicts septa growth rate more strongly than oxygen-18 concentration in the surrounding water. B) Male nautiloids tend to show higher concentrations of oxygen-18 than do female nautiloids inhabiting the same point in the water column. C) Regardless of sox nautiloids spend most of their lives at depths of 200 meters or greater, where oxygen-18 concentration s typically differ (D) Among nautiloids, there is no effect of sex on the uptake of oxygen -18 from water or its deposition in septa.