A. Indifferent gonad.
B. Mesonephric duct.
C. Paramesonephric duct.
D. Muller’s tubercle.
The embryological structure shown as 1 in the photograph above represents Mesonephric duct.
The mesonephric duct (also known as Wolffian duct, archinephric duct, Leydig’s duct and nephric duct) is a paired organ found in mammals including humans during embryogenesis.