Final answer:
Portland cement is not a mineral because, according to the definition, minerals cannot be man-made and Portland cement is a manufactured product.
Step-by-step explanation:
Based on the definition of minerals, the correct statement about Portland cement is that c) Portland cement is not a mineral because minerals are not man-made. A mineral is a naturally occurring, inorganic solid with a definite chemical composition and a characteristic crystalline structure. Portland cement, however, is a man-made product and thus does not meet the criteria to be classified as a mineral, even though it may contain inorganic materials and harden when mixed with water.