The third option "Rhyolitic" would be your answer.
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
It is b) angle B.
The opposite angles of opposite sides are proportional to each other. So the smallest side’s opposite angle will be the smallest angle, and in this case, since the largest side is 12, the opposite angle, B, will be the largest angle.
Also, make sure to check to see if the question is the right subject, hope this helps
