Asubstance is composed of only one kind of atom and can't be separated into simpler substances or converted into another substance by chemical processes.
under which category would you classify this substance?
a) element
b) compound
c) solution
d) suspension

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