Answer the following question given this paragraph: 

We all start as a single cell and soon grow into an embryo. Notice the remarkable details beginning to form. The eyes, backbone, and limb buds are obvious. Think about the amazing complexity that must be going on inside the embryo, and the tremendous amount of growth and development still to come. So, yes, at one time we all looked similar.


Q: We all start as a single cell and soon grow into what?

 Choices:

- nucleus

- uterus

- egg

- embryo

A:
embryo
