While Studying a Group of Ammonites (An Extinct Lineage of Cephalopods)

While studying a group of ammonites (an extinct lineage of cephalopods) that lived during the Mesozoic, you measure the shell diameter of different fossil ammonite species. The table represents the data you collected for each of six different time periods. To what rule does the data conform? $\begin{array} { | l | l | } \hline \text { Time interval } & \text { Mean shell diameter } ( + / - \text { standard error } ) \\\hline 245 - 214 \text { MYA } & 15 \mathrm {~mm} ( + / - 5 \mathrm {~mm} ) \\\hline 215 - 184 \text { MYA } & 21 \mathrm {~mm} ( + / - 7 \mathrm {~mm} ) \\\hline 185 - 154 \text { MYA } & 36 \mathrm {~mm} ( + / - 12 \mathrm {~mm} ) \\\hline 155 - 124 \text { MYA } & 63 \mathrm {~mm} ( + / - 21 \mathrm {~mm} ) \\\hline 125 - 94 \text { MYA } & 72 \mathrm {~mm} ( + / - 24 \mathrm {~mm} ) \\\hline 95 - 65 \text { MYA } & 84 \mathrm {~mm} ( + / - 28 \mathrm {~mm} ) \\\hline\end{array}$

A) biogenetic rule
B) Allen's rule
C) Cope's rule
D) Bergmann's rule