Does the answer from the textbook even make the slightest sense? How can there be three carbons?
If it is C3H5F, there two missing. Why don't they put the two cases where fluorine is not connected to the double bonds?
Which textbook is this?
Definitely something is wrong with the question. Either "all" or only a subset, either of C2XXX or C3XXX.
This is solomon's Organic Chemistry, edition 11. I think they meant C3H5F. If so, there is one isomer missing.
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