Which statement correctly explains why you cannot apply the product rule to simplify $2^3\times 3^3$ by adding exponents?

• A. Add the bases first, then multiply the exponents. The product rule applies only after combining bases by multiplication, which is not valid here.
• B. You can only apply the product rule when both bases are prime numbers, and since 2 and 3 are prime, this is allowed.
• C. You can add the exponents because both bases have the same exponent, which is 3, so the result is ${(2+3)}^3$.
• D. You cannot add exponents because the bases are different (2 and 3); the product rule $a^m\times a^n$ applies only when both factors have the same base.

Answer: (D)