Concept:Monocotyledonous crops have only one seed leaf, or cotyledon, in their seeds.
Explanation:Common monocotyledonous crops include cereals, palms, and plantains.
Oil palm, rice, and plantain all belong to this monocot group.
Options B, C, and D list mostly dicotyledonous crops.
Therefore, the correct set is oil palm, rice, and plantain.
Answer:A. oil palm, rice, and plantain.