I am new and learning more about deadlock. recently we got this in production environment and not sure what it is telling me. Any help to resolve this, really appreciate it.

index code:
CREATE NONCLUSTERED INDEX [IX_arb] ON [dbo].[arb]
(
[set_id] ASC
)
INCLUDE([it_flg],[con_cd],[h_s],[e_cd])
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF,
DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON,
FILLFACTOR = 100) ON [INDEXES]
GO