1.If a geologist found two fossils of different species buried next to each other in a rock layer, he or she might hypothesize that the two organisms may have been alive during the same time period.

true***
false

2.How do layers B and D compare in age? If rock layers between B and D have eroded away, what is the boundary between B and D called?

They're both true.

Sorry, for #1 I picked false.

OH, never mind....

what about #2?

true #2

To answer the first question, the geologist may make the hypothesis that two different species found buried next to each other in a rock layer were alive during the same time period. This hypothesis is true.

In response to the second question, if rock layers between B and D have eroded away, the boundary between B and D is called an unconformity.