昨夜は風が強かった〇〇、庭の木の葉が全部落ちている。What should be included in 〇〇?

Question

While practicing for the upcoming JLPT exam, I came across this question

昨夜は風が強かった〇〇、庭の木の葉が全部落ちている。

A. はずで　　B. たびに　　C. によって　　D. とみえて

For B. たびに, I understand that it should be used for something that happens regularly, so it is unlikely to be this choice because of 昨夜.

For C. によって, though it can imply the cause/reason, I understand that it should be used after a noun, so it is unlikely to be this choice as well.

Now as for D. とみえて, I found a similar example as below making me to decide to go with this choice.

雨が降ったとみえて、道が濡れています。

However, after showing this question to my Japanese friend, she suggested that among all these choices, she would pick A. はずで.

Now I started to get confuse of what should be an appropriate answer here. Is it possible for someone to kindly elaborate on why one should be used here instead of another?

Answer 1

昨夜{さくや}は風{かぜ}が強{つよ}かった〇〇、庭{にわ}の木の葉{は}が全部[落]{お}ちている。

A. はずで　　B. たびに　　C. によって　　D. とみえて

To me, the correct answer would be D. とみえて. 「～～と見{み}える」 is an expression of conjecture based on a reason or grounds -- "it must ~~", "it must have been ~~", etc.

Conjecture: 昨夜は風が強かった "it was very windy last night"

Grounds: 庭の木の葉が全部落ちている "all the tree leaves have fallen in the yard"

There arises absolutely no unnaturalness if the sentence is formed using 「とみえて」.

B. たびに and C. によって are just impossible precisely for the reasons that you yourself stated.

A. はずで is not nearly as natural-sounding as D. とみえて while I might not necessarily call it 'incorrect'. Why not very natural?

「はず（だ）」 expresses conviction or firm belief and the most common position it takes in a sentence is at the very end. Using it mid-sentence by turning it into its continuative form 「はずで」 is not very common. Thus, if the sentence were:

「庭の木の葉が全部落ちている。昨夜は（相当{そうとう}）風が強かったはずだ。」

then, it would be much better.

In addition, IMHO, 「はずで」 would be too strong a word choice compared to 「とみえて」 in this particular sentence. The speaker is not conducting an investigation here. S/he is merely stating his/her conjecture regarding last night's weather that seems to have caused the leaves to fall.