It can be inferred from paragraph 2 that Agassiz and other geologists of his time were not able to determine A. which geographic regions had been covered with ice sheets in the last ice age B. the exact dates at which drifts had been deposited during the last ice age C. the exact composition of the drifts laid during the last ice age D. how far south along the east coast of the United States the ice had advanced during the last ice age