How do the electron configurations within the same group of elements compare?

The electronic configuration of the elements which share the group, must have the last electron in same block..

Ibelieve its a because an empirical formula usually has a ch in it your options are a or b

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later