Correct option is C
Boron trifluoride etherate, strictly boron trifluoride diethyl etherate, or boron trifluoride–ether complex, is the chemical compound with the formula
often abbreviated
It is a colorless liquid, although older samples can appear brown. The compound is used as a source of boron trifluoride in many chemical reactions that require a Lewis acid.
Boron trifluoride etherate serves as a source of boron trifluoride according to the equilibrium:
The BF3 binds to even weak Lewis bases, inducing reactions of the resulting adducts with nucleophiles.
