Final answer:
Monocytes are the white blood cells that transform into macrophages, which are linked to chronic infections due to their phagocytic ability to engulf pathogens and promote inflammation.
Step-by-step explanation:
The type of white blood cells that, upon maturation, transform into macrophages commonly linked to chronic infections are monocytes. Monocytes are a type of white blood cell that circulates in the blood and lymph and differentiates into macrophages after moving into infected tissue. These macrophages are phagocytic, which means they are capable of engulfing and digesting cellular debris and pathogens. Monocytes and the macrophages they become play a significant role in the immune system by phagocytizing pathogens and helping to promote inflammation when necessary, contributing to the body's defense mechanisms against chronic infections.