Which one among the following is not a plantation crop?

A plantation crop is a commercial cash crop grown on large monoculture estates using intensive capital and labour, and it typically requires industrial-scale processing soon after harvest before it can be sold — such as withering/rolling/drying, pulping/fermenting, or tapping/coagulating. This is distinct from an ordinary food (cereal) crop, which is grown mainly for direct domestic consumption as a staple grain on regular farms.

Applying this to the given options: Tea, Coffee, and Rubber are each grown on large estates and each requires dedicated processing before reaching the market, while Wheat is a cereal grown as a Rabi-season staple food crop on ordinary farms mainly for domestic consumption.

• Wheat — a cereal (Rabi-season) food grain grown on ordinary farms mainly for domestic consumption; needs no estate-scale processing before it can be sold as food, so it does not fit the plantation-crop model.

• Tea — grown on large monoculture estates; leaves are withered, rolled and dried before marketing — fits the plantation-crop model.

• Coffee — grown on extensive estates, often under shade trees; berries are pulped, fermented and dried before sale — fits the plantation-crop model.

• Rubber — grown on large estates; latex is tapped and coagulated into sheets before sale — fits the plantation-crop model.

Cross-checking against the standard definition of plantation agriculture (large-scale monoculture, capital-intensive, processing-dependent, primarily commercial/export-oriented) confirms that Tea, Coffee and Rubber satisfy every criterion while Wheat satisfies none of them, so Wheat is the crop that is not a plantation crop.