Answer: c) blastocyts
Step-by-step explanation:
A stem cell is a cell which has the quality to develop into special cell types in the body to perform variety of functions in the body. These cells can be used in the body to replace other cells in the body when the cells are damaged, diseased and do not perform their functions.
A blastocysts is a group of stem cells which develops in the early embryonic life after continuous differentiation. These cells divide and differentiate so as to develop specialized cells which gives rise to body organs with associated functions in the developing fetus.