The source of materials which eventually formed our vast coal and oil deposits came from ( plant & animal matter, volcanic ash, rocks) buried in (ingenious, metamorphic, sedimentary) rocks all over the earth.

Answer : The source of materials which eventually formed our vast coal and oil deposits came from Plant and animal matter buried in sedimentary rocks all over the earth.

Explanation : As we know that we get the coal and oil from the fossil fuels which are nothing but the dead and decayed bodies of plants and animals.

By the process of sedimentation of rocks the layers got formed over the fossils turning it into fuels after decades. 

Only one reactant yields 2 or more products. meaning you will only have 1 product and it will break down into 2 or more products. eg. h2o -> h2 + o2