While collecting samples of rocks, if a scientist collects several that contain fossils, the most likely type of rock that his sample is going to be is C. sedimentary rock. Sedimentary rocks are the most common types of rocks, and can be found almost everywhere. This may be the very reason why most of the fossils found over time are located in these very rocks. So, if there is a fossil, it will most likely be found in a sedimentary rock.