Final answer:
The description provided refers to Staphylococcus aureus. S. aureus is a Gram-positive bacterium that forms clusters of round, smooth, convex, and glistening colonies. It can cause various infections and is medically significant.
Step-by-step explanation:
The description provided refers to Staphylococcus aureus (a). Staphylococcus aureus is a Gram-positive bacterium that is characterized by forming clusters of round, smooth, convex, and glistening colonies. It can also appear opaque with an entire edge and butter-like (butyrous) consistency. S. aureus is a medically important species that can cause a wide range of infections and diseases.