Which of these must occur during s phase of the cell cycle so that two daughter cells can be produced during m phase? (1 point) a-the dna must be replicated. b-the chromosomes must be joined. c-the cytoplasm must be separated. d-the cell membrane must be expanded,

During the S phase in the cell cycle, the chromosomes are replicated so that there are two copies. These copies are necessary so that each daughter cell created during the M phase will have an identical copy of the DNA.

Therefore, the answer is A: The DNA must be replicated. 

The chromosomes joining, cell membrane expanding, and cytoplasm separating all happen during the M phase (mitosis).

The light is great source of energy