In a 2 months old infant undergoing surgery for biliary atresia, you would avoid one of the following anaesthetic –
The child with biliary atresia will have hepatic dysfunction.
Sevoflurane, thiopentone and propofol are safe in liver disease.
Halothane is not contraindicated in pre-existing liver :-

"There is no compelling evidence associated with worsening of pre-existing liver disease". 
─Morgan
"Pre-existing liver disease unrelated to halothane is not a contraindication to the use of halothane".
—Lee 13th/e 143

Though not a contraindication, halothane should be avoided in liver disease -

"Potentialy hepatotoxic drug should be avoided".
 —Lee 55
Thiopentone
Halothane
Propofol
Sevoflurane