The mean birth weight of first-born infants of 23 women who smoked more than one pack of cigarettes per day during pregnancy was 200g lower than that...

The mean birth weight of first-born infants of 23 women who smoked more than one pack of cigarettes per day during pregnancy was 200g lower than that of the first-born infants of 16 women who never smoked. The difference was statistically significant at the 5% level (p < 0.05). This means which of the following?

A. Smoking during pregnancy causes intrauterine fetal restriction.

B. smoking during pregnancy is associated with intrauterine fetal growth restriction

C. The difference observed between mean birth weights was too large to have occurred by chance alone.

D. We reject the null hypothesis

E. B, C, and D are correct interpretations