Artery to bleed in duodenal ulcer haemorrhage -
Gastro duodenal artery is the most common artery involved in duodenal ulcer hemorrhage.

Also, remember

A peptic ulcer is the most common cause of massive upper gastrointestinal bleed (Duodenal ulcers > Gastric ulcers)
Bleeding ulcers in the duodenum are usually located on the posterior surface of the duodenal bulb.
Splenic artery
Gastroduodenal artery
Left gastric artery
Sup. mesenteric artery