13.
Your Answer is
Correct Answer is A
Explanation
According to the sentence meaning "Wegman's Weimaraner led the life of an ordinary dog ??in most aspects", most here is the adjective part of speech "most", so A is correct.
Item C: More needs to have a clear comparison object for the comparative level, and it needs to appear in pairs with than, so it is wrong.
Item B: much modifies uncountable nouns.
Item D: mostly "mainly" adverbs, which cannot modify nouns.