为了验证该知识，小杨同学设计进行了下面实验．请根据这一实验分析回答问题．

①两个盛有潮湿的、肥沃土壤的花盆，编号为甲、乙．

②将挑选好的马铃薯块茎切成大小相等的小块若干，分成两组，将有芽眼马铃薯块茎种在甲花盆内，将没有芽眼马铃薯块茎种在乙花盆内．将两花盆放在相同的适宜条件下培养，一段时间后观察．

1a 植物无花，无种子，以孢子繁殖···························································2

1b 植物有花，以种子繁殖······································································3

2a 小形绿色植物，结构简单，仅有茎、叶之分···········································A

2b 通常为中形或大形草本，很少为木本植物，分化为根、茎、叶···················B

3a 胚珠裸露，不包于子房内···································································C

3b 胚珠包于子房内···············································································D