Final answer:
The true statement about the expression 4 + 2x is D. 4 + 2x is a sum. The coefficient of x in the expression is 2, and there is only one variable present.
Step-by-step explanation:
The statement about 4 + 2x that is true is D. 4 + 2x is a sum. This expression is composed of two terms, the constant 4 and the variable term 2x, which are being added together. The value in front of the variable x is called the coefficient, and in this expression, the coefficient of x is 2, not 4. Therefore, statement B is incorrect. Additionally, there is only one variable present in the expression, and that is x, making statement C incorrect. Statement A is also incorrect as 4 + 2x is not a product, which would indicate multiplication between terms.