【单选题】
A <{p}>smoking rates among youth have declined very little<{br/}><{/p}>
B <{p}>there are now more female than male smokers among high school seniors<{br/}><{/p}>
C <{p}>high smoking rates are due to the increase in wealth<{br/}><{/p}>
D <{p}>smoking at high school are from low socio-economic backgrounds<{br/}><{/p}>
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