Between D and E I used below logic:
<noun> has become a consideration. To represent a noun in a phrase the best way is to use a "that" phrase. If we do not use "that" we don't know what has become a consideration - is it the supply of oil/being finite/supply of oil being finite
Does anyone know where Fanatico got this information from? I would like to look into this so that I can better understand why we use "That" to start the sentence off. I originally chose D and was skeptical about E at first due to it sounding awkward with "that."