GMAT Sentence Correction (SC) | Re: James Joyce wrote the novel Ulysses through the teens and published it

Dear friend,mikemcgarry
Does subordinate conjunction always require[noun] +[verb][/b] structure? Somehow I came to know that subordinating conjunction can be followed bya noun or a sentence , depending on the meaning. I may be wrong, but to be confirmed I am citing few sentences below:

After lunch, I felt sleepy.
After
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