[单项选择] Old Mothers’ Children Have Higher Diabetes (糖尿病) Risk Children of older mothers run a higher risk of developing insulin-dependent (胰岛素依赖型的) diabetes, the British Medical Journal said. "A strong association was found between increasing maternal (母亲的) age at delivery and risk of (insulin-dependent) diabetes in the child. Risk was highest in firstborn children and decreased progressively with higher birth order," Professor Edwin Gale and colleagues at Southmead Hospital in Bristol said. Diabetes is a serious, incurable, lifelong disease characterized (以......作为特性) by all inability to control the amount of sugar in the blood. Insulin-dependent diabetes, which mainly affects children, is treated by administering the hormone insulin. Gale looked into 1,375 families in the Oxford area where one or more children had diabetes and found that the risk of a child developing insulin-dependent diabetes increased by 25 percent for each five-year band of the mothers age. The ri
A. the amount of sugar he or she consumes
B. the age of the father
C. birth order
D. the maternal age at delivery