RDF -- venn diagram for resources, literals, properties, statements?

I am trying to understand the Venn diagram for the following sets
used in the RDF data model
(http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/ Section 5)

1. Resources
2. Literals
3. Properties (proper subset of resources)
4. Statements

I suspect the following are true and would appreciate either pointers to
what in the spec makes them true or counter-examples:

(a) No literal is a resource

(b) No property is a statement

(c) Some statements are resources others are not.

(d) No literal is a statement

Thanks,

- Waqar Hasan