Answer
a. during the first trimester
Work Step by Step
Organogenesis is the development of the organs that begins during the third to eighth week and continues until birth. Some organs, like the lungs, continue to develop after birth.
There are three trimesters in pregnancy: the first trimester, which lasts from the first week to the 13th week, the second trimester, which lasts from the 14th week to the 27th week, and the third trimester, which lasts from week 28 to week 40 (and up).
