The correct option is C Poaceae
Spike of spikelets inflorescences commonly occurs in Poaceae. Flowers of Poaceae are characteristically arranged in spikelets, each spikelet having one or more florets. The spikelets are further grouped into panicles or spikes. A spikelet consists of two bracts at the base, called as glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external the lemma and one internal palea.
Therefore, the correct answer is option C.