Explanation
The rock with the lowest primary porosity among the following options is:
B: Granite.
Granite is an igneous rock that is composed mainly of quartz, feldspar, and mica minerals. It is a relatively dense and crystalline rock with low primary porosity. Primary porosity refers to the inherent pore spaces within the rock that are formed during the rock's formation. In the case of granite, the intergranular spaces between the mineral grains are typically minimal, resulting in low primary porosity. As a result, granite has low permeability and is not conducive to the flow of fluids such as water or hydrocarbons.
