Which blood cell type is elevated at birth but decreases to adult levels during the first year of life?

The correct answer is monocyte

Explanation:

The largest white blood cell in the circulation is monocyte. A high level of monocyte indicates inflammation and chronic infection. During birth, the monocyte level becomes elevated as compared to adults.

These monocyte plays an important role in providing innate immunity to the neonate because during birth the child is at the great risk of getting infection. Monocyte can be differentiated into dendritic cell or tissue macrophages and destroy pathogens in neonates. Therefore the correct answer is monocyte.