Answer:
When oestrogen rises to a high enough level it causes a surge in LH from the pituitary which causes ovulation where an egg is released from the follicle (Day 14 of the cycle). The follicle becomes the corpus luteum and this produces oestrogen and progesterone which inhibit FSH and LH production by the pituitary.
Explanation:
Its has to be A that's just plain common sense
I'd go with 'the cells won't be able to produce energy' since oxygen is crucial for cellular respiration and cellular respiration is what releases energy!
Hope it helps! <3
I believe the answer is B.2