Not to labour the point too much but if the intention of the question was to elicit an answer to 'why can't Enterprise Manager see the local drives' then I reckon the answer was phrased wrong
It's good to see that also native english speaker have problems with these questions. For me, understanding the question is the first hurdle, second is translating the meaning and intention, third is when phrases like 'at least', 'most likely', 'least likely' and the like are used. This always leaves a huge uncertainty.
However, I like taking the questions, even if I fail!