Assertion n reason: 1.A:progesterone secretion during the second n third trimester of pregnancy is a measure of functional status of corpus luteum R:corpus luteum secretes progesterone hormone for the maintenance of pregnancy

Assertion is incorrect while the reason is correct. 
Progesterone released by the corpus luteum in the first trimester is important for the maintenance of early pregnancy (first trimester) till the placenta is formed. In the second and third trimester placenta takes the function of secretion of various hormones including progestogens.