Light Reactions : ATP :: Calvin Cycle :
a. G3P
b. H2O
c. O2
d. H+

a. G3P

Explanation:

Photosynthesis is the process by which plants synthesize their food from inorganic sources in the presence of light. The photosynthetic process occurs in two stages namely: light dependent stage (light reaction) and light independent stage (Calvin cycle).

The light stage primarily functions to synthesize ATP and NADPH products needed in the Calvin cycle to synthesize sugar (glucose). However, the CALVIN CYCLE produces a three-carbon compound called GLYCERALDEHYDE-3-PHOSPHATE (G-3-P) as one of the precursors of glucose.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.