The correct option is C Spikelet
In Graminae, the basic unit of the inflorescence is called as spikelet. it is typically consisting of a basal pair of minute sterile bracts called as glumes and one or more distichously arranged distal florets on an often zigzag extension of the spikelet axis called as the rachilla. Each floret is typically embraced by an additional pair of minute chaffy bracts called as the lemma and the palea. The florets are unisexual or bisexual and have usually two or three barely recognizable structures called as lodicules, that may represent a vestigial whorl of perianth, that forces the lemma and palea apart during anthesis, thereby facilitating exertion of the stamens and stigmas.