Determine whether the following is a Lewis acid or a Lewis base
PH₂CH₂
BF₃
AlCl₃
Br^-

• A. Lewis Acid, Lewis Acid, Lewis Base, Lewis Base
• B. Lewis Base, Lewis Base, Lewis Acid, Lewis Acid
• C. Lewis Base, Lewis Acid, Lewis Acid, Lewis Base
• D. Lewis Acid, Lewis Base, Lewis Base, Lewis Acid

Answer: (C)