The Small Size of Boron Prevents It from Forming Compounds

Multiple Choice

The small size of boron prevents it from forming compounds in which it have more than four nearest neighbors. Thus, BF₃ forms the only coordinate the:

A) single-coordinate, mono BF⁻ ion.
B) double-coordinate, bent BF₂⁻ ion.
C) three-coordinate, trigonal BF₃⁻ ion.
D) four-coordinate, tetrahedral BF₄⁻ ion.
E) six-coordinate, octahedral BF₆^- ion.