Answer:
The correct option is A) Â 1, 2, 3, 4, 7
Explanation:
As the walls of the cells are narrow and have microvilli, we can predict that the phenomenon of transferring materials by any means such as active transport might be  occurring in the tissue.
Every tissue will have an epithelium and since the tissue has a single layer of cells only we can predict that the cells might  be having a simple epithelium.
The presence of uni-layer or single cells also makes us infer that the tissue has columnar epithelium.
The presence of microvilli also suggest that secretion by exocytosis might be occurring in these tissues.