To apply the Distributive Property to multiply \( 3a^3b^2(6ab + 7a^2b) \), we need to distribute \( 3a^3b^2 \) to each term inside the parentheses.
- Multiply \( 3a^3b^2 \) by \( 6ab \):
\[ 3a^3b^2 \cdot 6ab = 18a^{3+1}b^{2+1} = 18a^4b^3 \]
- Multiply \( 3a^3b^2 \) by \( 7a^2b \):
\[ 3a^3b^2 \cdot 7a^2b = 21a^{3+2}b^{2+1} = 21a^5b^3 \]
Now, combining both results gives:
\[ 18a^4b^3 + 21a^5b^3 \]
Thus, the correct answer is:
18a^4b^3 + 21a^5b^3