Sedimentary Rock
Here's Why:
Fossils also form from molds and casts. If an organism completely dissolves in sedimentary rock, it can leave an impression of its exterior in the rock, called an external mold.
I got this information from http://www.livescience.com/37781-how-do-fossils
I hope this helps:)
Answer:
b because it is the cheapest option
Explanation:
Possible motives for murder include lust, loathing, jealously, a serious yearn for money, vengeance, etc.