Steels with high carbon equivalent have poor Weldability, because in these steels during welding________________?

Steels with high carbon equivalent have poor Weldability, because in these steels during welding________________?

A. Carbon and other alloying elements get oxidised from the weld pool
B. Excessive ferrite forms in the heat affected zone leading to poor toughness of the weld
C. Martensite forms in the heat affected zone leading to poor toughness/ductility of the weld
D. Segregation of carbon and other element occurs in the weld pool leading to poor properties of
the weld