What Has Research Found: Does Marriage Cause Happiness, Better Health

What has research found: does marriage cause happiness, better health, or better finances or are happier, healthier, and wealthier people more likely to marry in the first place?

A) Marriage causes happiness.
B) Happier people are more likely to marry.
C) Both: marriage causes happiness, good health, and better finances, and happier, healthier, and wealthier people are likely to marry.
D) Neither: marriage does not seem to cause happiness, and there is no evidence that happier people are likely to marry.