Final answer:
Ed's ability to provide complex and better solutions due to his 25-year experience as a tax attorney best illustrates crystallized intelligence, which involves using acquired knowledge effectively.
Step-by-step explanation:
The fact that Ed's solutions are more complex and better due to his experience as a tax attorney illustrates the concept of crystallized intelligence. Crystallized intelligence is characterized by acquired knowledge and the ability to retrieve it, which is something that Ed would have developed over his 25 years of experience in his field. As he ages, although his fluid intelligence, the ability to see complex relationships and solve new problems quickly, might have declined, his crystallized intelligence allows him to draw on his extensive experience to provide complex solutions.