Answer:
A and B only
Explanation:
At the G1 checkpoint the cell checks that the cell being divided is the right size and has enough energy reserves to complete the cycle, the cell also checks if there is damage to the DNA. If the cell does not meet the correct standards, the cell cycle halts for a possible fix of the problem or cell could enter the G0 stage where it awaits further instructions.
If the cell passes the G1 checkpoint it is fully committed to the process of cell division and can not reverse the process.
