The question wants one plant whose carpels stay separate (apocarpous) and a second plant whose carpels are fused into one unit (syncarpous), in that order.
- Hibiscus, papaver: Hibiscus actually has a syncarpous ovary with fused carpels, not an apocarpous one, so it cannot fill the first slot correctly.
- Hibiscus, Annona: The same problem applies here. Hibiscus is syncarpous, so putting it in the apocarpous slot is wrong regardless of what fills the second slot.
- Annona, Michelia: Annona (custard apple) has many free, separate carpels sitting side by side on the same receptacle, the definition of apocarpous. Michelia has its carpels fused into a single compound ovary, which is syncarpous. This order matches the question exactly.
- Papaver, Michelia: Papaver (poppy) is syncarpous, with fused carpels forming a capsule, so it fails as an example of an apocarpous ovary, even though Michelia correctly fills the syncarpous slot.
Only the third option places a genuinely apocarpous plant first and a genuinely syncarpous plant second, so Annona and Michelia is the correct pair.
Let's summarize:
- Apocarpous: carpels free and separate, as in Annona.
- Syncarpous: carpels fused into one ovary, as in Michelia and Hibiscus.
- Papaver is syncarpous too, so it cannot represent the apocarpous example.
So the correct pair, apocarpous then syncarpous, is Annona and Michelia.