According to psychologist Dean Burnett, people feel down in January 29 post-holiday discontent, and the Blue Monday claim makes it seem like there are scientific reasons for this.
答案：(B) owing to
【句型】owing to 字詞搭配「由於」，表示「人們一月心情低落是由於假期後的不滿情緒」；as for（至於）、in spite of（儘管）、with respect to（關於）都不合。
四個選項都是幾個字合起來當一個介系詞用（劍橋 English Grammar Today 的 Prepositions 條目），後面都能接 post-holiday discontent，所以句型上一個都刪不掉，只能純比邏輯關係。要問的是：假期後的失落感，和一月心情低落之間，是什麼關係？
句子是 people feel down in January ___ post-holiday discontent（人們在一月心情低落，___ 假期後的失落感）。放完長假回到日常，心情跟著往下掉——失落感是心情低落的原因，所以要用表原因的 owing to（由於）。後半句 the Blue Monday claim makes it seem like there are scientific reasons for this（憂鬱星期一的說法讓這件事看起來像有科學原因）裡的 reasons（原因）也回頭印證：這一段談的就是成因。
in spite of（儘管）是讓步，方向相反——變成「雖然有失落感，人們卻心情低落」，前後矛盾。這個字和上一批 112 年第 15 格的 Despite 是同一組，都要接名詞，也都常拿來當這種因果題的誘答選項。as for（至於）和 with respect to（關於）都是「帶出話題」用的，只是換個題目來談，說不出兩件事的因果關係，而本句需要的正是因果。
owing to ＋ 名詞（由於……）、due to ＋ 名詞（由於……，與 owing to 同義）、because of ＋ 名詞（因為……）、in spite of ＋ 名詞（儘管……）、as for（至於）、with respect to（關於）、feel down（心情低落）。
The idea of Blue Monday dates back to a 2005 campaign by Sky Travel. The travel company wanted to 26 people to take January vacations, so they reached out to a psychologist. The scholar then developed an equation to find the most depressing day of the year, and it turned out to be the third Monday in January. Since then, other companies have jumped on the bandwagon to promote everything from soft drinks to new clothes as a 27 . A group in the UK even started a website devoted to "beating Blue Monday."
Many scientists, however, say there is no evidence that Blue Monday causes any more sadness than other specific days of the year. 28 , the idea of Blue Monday persists. According to psychologist Dean Burnett, people feel down in January 29 post-holiday discontent, and the Blue Monday claim makes it seem like there are scientific reasons for this. Also, the idea 30 a very complex issue regarding depression into something simple and easily understandable, and that tends to appeal to a lot of people.