单选题：Since the mid-1970s, when it became clear that the number of

Since the mid-1970s, when it became clear that the number of births was resolutely declining, Japanese governments have made efforts to encourage people to have more babies. But for all that they have increased child benefits and provided day-care centres in the past 30 years, the birth rate has remained stubbornly low．One reason is that in Japan, unlike in the West, marriage is still more or less a prerequisite for having children．Only 2% of births take place out of wedlock. And weddings cost a lot of money. The more elaborate sort may involve renting a chocolate-box “church” and hiring or buying at least three bridal outfits.
Having gone to all that trouble, married couples do, in fact, have an average of slightly more than two children, just above what is needed for births to exceed deaths. ① The trouble is that fewer and fewer people get married. Women wait ever longer and increasingly do not bother at all. According to the NIPSSR, six out of ten women in their mid-to-late 20s, which used to be the peak child-bearing age, are still unwed. ②
But the cost of weddings may be the least of the reasons why the Japanese are increasingly putting off marriage or avoiding it altogether. One weightier one is that employment rates among women have increased but private companies implicitly discourage mothers from returning to their old jobs．Toshiaki Tachibanaki， an economist who has written on inequality among Japanese women, finds that about 80% of female civil servants return to their old jobs after having children because they get reasonable maternity benefits and help with childcare. ③ But in private companies they are typically less well looked after, and only about a third go back to work．
It does not help that unemployment is high and incomes are low among the young-especially among young men, who increasingly give up even looking for jobs. One of Japan's most prominent sociologists, Masahiro Yamada of Chuo University, thinks that most young Japanese women still want to be housewives, but are struggling to find a breadwinner who earns enough to support them. ④ He points out that half the young people of prime marrying age—20-34—still live with their parents. In the 1990s he coined the term "parasite singles" to describe them. They seemed to be getting a good deal, saving money on rent and spending it on foreign travel and luxury goods instead. If they wanted privacy, they could always go to one of Japan's ubiquitous love hotels.
阅读以上文章，回答题The word “prerequisite”in Paragraph One probably means __________． A． premise
B． requirement
C． restriction
D． result