How does the relationship between K_a and K_b help in understanding polyprotic acids?

• A. K_a is always larger than K_b for polyprotic acids.
• B. K_a and K_b are unrelated and do not provide any useful information.
• C. K_b is always larger than K_a for polyprotic acids.
• D. K_a and K_b are inversely related, helping to understand the acid-base behavior of polyprotic acids.

Answer: (D)