Question

Fiona is very angry ________ her boss's decision to sack several members of staff.
fill in the blank

Answer 1

Fiona is very angry *with* her boss decision to sack several members of staff.

Answer 2

Answer:

"Fiona is very angry about her boss's decision to sack several members of staff".

A preposition adds meaning to a sentence. In any sentence, a "preposition" exemplifies the relationship between a "pronoun" or a "noun" and "another element" or a "word". "About" fits better as a preposition in the above sentence because it helps to clearly show the relation between Fiona’s (noun) anger regarding a decision (other element or factor).