Hey,
These can be tricky because you can only use the information given and not extrapolate outwards (even though they don't complete carbon's 4 bonds and imply it is attached to another thing)
Note that the question is asking for complete residues, of which F and I are completely there.
However they are trying to trick you with G. For you to get out a complete amino acid residue, you need it to have an NH2 and a COOH group.
Here it is not shown that G has an attached C=O, only a NH.
Because of this, we can only count F and I as they have NH and C=O termini.
Which is sad because it no longer spells FIG )':
Please let me know if this is unclear!