Read the following passage and mark the letter A, B, C or D on your answer sheet

Read the following passage and mark the letter A, B, C or D on your answer sheet to choose the word or phrase that best fits each other numbered blanks.
MARITAL PROBLEMS
When people marry, they're usually in love and happy to be tying the (46) _______. But after that, things tend to change. On average, couples' satisfaction with their marriage declines during the first years of marriage and, if the decline is particularly steep, divorce may follow. The course of true love runs downhill.
For around 30 years, researchers have studied how having children affects a marriage, and the results are (47) ________: the relationship between spouses suffers once kids come along. Comparing couples with and without children, researchers found (48) _________ the rate of the decline in relationship satisfaction is nearly twice as steep for couples who have children than for childless couples. In the (49) ________ that a pregnancy is unplanned, the parents experience even greater negative impacts (50) ________ their relationship.
The irony is that even as the marital satisfaction of new parents declines, the likelihood of them divorcing also declines. So, having children may make you miserable, but you'll be miserable together.
(https://www.theguardian.com)