There is ____ universal concept among ____ parents that the more they feed their kids, the healthier they will grow up to be.

A．an, the

B．a, the

C．a, /

D．/, the

下列四项去掉哪一项后，剩下的图形可以呈现出一定的规律性（）.

A.A

B.B

C.C

D.D