Let's evaluate each option using the order of operations:

• Option A: $20 - 5 \times 2$ Multiplication first: $5 \times 2 = 10$ Then subtraction: $20 - 10 = 10$. Since $10 \neq 30$, statement A is false.
• Option B: $15 \div 3 + 4$ Division first: $15 \div 3 = 5$ Then addition: $5 + 4 = 9$. Since $9 = 9$, statement B is true.
• Option C: $10 + 8 \div 2$ Division first: $8 \div 2 = 4$ Then addition: $10 + 4 = 14$. Since $14 \neq 9$, statement C is false.
• Option D: $2 \times (5 + 3)$ Parenthesis first: $5 + 3 = 8$ Then multiplication: $2 \times 8 = 16$. Since $16 \neq 13$, statement D is false. Therefore, only statement B is true.