—I am leaving for the States tomorrow for a holiday, Caroline!

—           

A．All the best!

B．Take your time.

C．Well done!

D．That’s OK.

用葡聚糖凝胶色谱分离下列化合物：大黄素、番泻苷B、大黄酚二葡萄糖苷和大黄酸葡萄糖苷，请排列洗脱次序。