Manish is studying the prenatal development of a fertilized egg. He observes that the fertilized egg is in its third week since conception and that the spinal cord is about to be formed. Which of the following periods in prenatal development is Manish most likely observing? a. the germinal period.
b. the embryonic period.

The embryonic period

Explanation:

The embryonic period is the period after implantation roughly starting from week 4 to week 11 , shows the development of the fertilized egg, In this early stage  of development , due to the rapid  cellular development the formation  of body organs and structures like the heart, primitive brain, spinal cord  are formed.  Three stages occurs in the embryonic stage which include The pre-embryonic stage, the embryonic period, and the fetal period.

Therefore if Manish is studying development of fertilized egg, of which the spinal cord is about to form, then he is most likely observing the The embryonic period.

i have to go with a for this one

answer; repetitive thoughts; ritualistic behaviors;