Bosentan is
It is a dual endothelial receptor antagonist. FDA has approved the use of Bosentan for Raynaud's phenomenan, pulmonary aery hypeension. Ref: HL Sharma 3rd ed,Vasoactive peptides
Endothelin receptor blocker
ACEI
IIb/IIIa receptor blocker
None of the above
Immunomodulators