The stability of atoms depends on whether or not their outer-most shell is filled with electrons. If the outer shell is filled, the atom is stable. Atoms with unfilled outer shells are unstable, and will usually form chemical bonds with other atoms to achieve stability.
Answer:
RNA because it is single-stranded and contains the sugar ribose.
Explanation:
The answer should be C, progesterone.
Progesterone is the hormone which can help maintain the lining of uterus and to further thicken it so that the uterus is prepared for implantation and the development of a baby. The level of progesterone is significantly rose after ovulation.
On the other hand, LH, luteinising hormone, is produced by oestrogen, another female hormone which will drop after ovulation. LH helps stimulate ovulation and prevent the development of other follicles, the origin of eggs, to form yellow body instead. Which yellow body is the one which stimulates the production of progesterone.
Last but not least, I believe D should be testosterone, and it is a male hormone so it will not be found in female normally.
Therefore, your answer should be C, progesterone.
