The fossils of cold blooded animals dated back to the end of the Cretaceous period and
in that the high concentration of iridium found in the thin layer of clay led researchers to abandon the climatic alteration theory as much as it did to develop a new hypothesis.
A. in that the high concentration of iridium found in the thin layer of clay led researchers to abandon the climatic alteration theory as much as it did to develop ---
the phrase 'in that' has no relevance in the context.
B. that the high concentration of iridium found in the thin layer of clay led researchers to abandon the climatic alteration theory and then also to develop. ----
The intrusive connector 'that' renders the whole construction a fragment.
C. the high concentration of iridium found in the thin layer of clay led researchers to abandon the climatic alteration theory and to subsequently develop ---
The correct choice with perfect parallelism between to abandon and to develop
D. high concentration of iridium found in the thin layer of clay led researchers to abandon the climatic alteration theory as much as developing t-----
to abandon and developing is unparallel.
E. he high concentration of iridium found in the thin layer of clay led researchers to abandon the climatic alteration theory in addition to developing --
same error as in D. to abandon and to developing is unparallel.