(c) (ii) and (iii)
A stoma closes when the plant does not need CO₂ for photosynthesis, and when water flows out of the guard cells, causing them to shrink.
Source: Life Processes, Section 5.2.1
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The textbook clearly states: "the plant closes these pores when it does not need carbon dioxide for photosynthesis" and "the pore closes if the guard cells shrink" (which happens when water flows out). Option (iv) is wrong — water flowing in causes the pore to open, not close.