Hi lsat2022, thank you for your question!
Simply put, the language of (A) does not violate rule 5. Even though at first glance (A) seems to be referring to more than one loaf, the use of the plural 'loaves' here is to refer to an unknown quantity, which could be one or more. It's sort of like asking someone if they have any siblings. You don't say "do you have any sibling?" The singular sounds odd! You don't know how many (if any) siblings they have at all! Instead, you ask if they have any siblings
. But alas, I am no grammar expert, so I'm not quite sure what the technical grammar rule here is called. Luckily, however, I do know the LSAT! So, let's try discussing this in more common terms.
If we look at (A), we can actually rephrase it in terms of conditional logic to better understand why the word 'loaves' does not pose an issue here. We know that the phrase "the only" can effectively be treated as a sufficient indicator (check out this great post for more information on different ways to understand the phrase "the only" viewtopic.php?t=7614
). With this in mind, we can diagram (A) to mean:
Oatmeal Loaves Unsliced Loaves
We can interpret these conditionals to mean "any (or all) unsliced loaves are oatmeal loaves." Well, if any unsliced loaves are oatmeal, do we have to have more than one unsliced loaf? No, that doesn't make sense! We could have one unsliced oatmeal loaf, and that's perfectly in line with the phrasing of the answer choice as well as the rest of the rules (we could have 1 unsliced oatmeal loaf and 5 sliced loaves of the other type(s)).
That said, if (A) actually restricted us to 2 or more unsliced loaves, you'd be correct regarding how such a rule would conflict with rule 5!
I hope this helps!