The graph shows the results of a study to determine whether there is a link between the number
of cigarettes smoked by a mother and the birth weight of her baby.
Which conclusions can be drawn from this graph?
1 As the number of cigarettes smoked increases, the weight of the baby always decreases.
2 Factors, other than smoking, affect the birth weight of a baby.
3 Nicotine, tar and carbon monoxide slow the growth of an unborn baby.
4 The majority of all smokers smoke between 10 and 35 cigarettes per day.
A 1, 2 and 3 B 2, 3 and 4 C 2 only D 3 only