<p>An amateur potter herself, the accountant offered to help the artist with this business accounts, complicated as they were by his unusual system of record keeping. No error</p>
<p>Could someone please explain why D is correct as written? It sounds funny. Is it an idiomatic phrase that I just need to know?</p>
<p>Thanks in advance!</p>
<p>haha, this same exact question was discussed in some other thread some time ago…
and yes, you just need to know it… “trim the fat”: complicated…by, that is a correct idiom.</p>
<p>there is no idiom in this sentence</p>
<p>you just have to define each word
the sentence is saying “…complicated because they were on the basis of his unusual system of record keeping”</p>
<p>Thanks a lot! - I got it now.</p>