Final answer:
The statement that is true regarding regular languages and context-free grammars (CFGs) is that context-free languages can be parsed using regular expressions.
Step-by-step explanation:
A regular language can be described by a regular expression and can be recognized by a finite state machine, while a context-free language can be described by a CFG and can be recognized by a pushdown automaton. It is not true that all regular languages are also context-free languages (option a) because there are regular languages that cannot be expressed by CFGs. Also, regular languages are not more powerful than context-free languages (option c) because context-free languages are capable of describing more complex structures.
Hence, the statement that is true regarding regular languages and context-free grammars (CFGs) is d. context-free languages can be parsed using regular expressions.