Answer will be stoma. Stoma is a surgical opening in the large inestine for artificial removal of faeces. Whereas all the other options are parts of a chloroplast, present in plant cell. Stroma is the matrix of chloroplast, lamellae are the membranous structures like grana and stroma lamellae(fret channels) and quantasome are present in grana which are the main site of working of the pigment systems.
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