Final answer:
The expression 50m + 18m in simplest form is A) 68m. It is the result of adding the coefficients of the like terms, which both contain the variable 'm'.
Step-by-step explanation:
The expression 50m + 18m combines two terms that are like terms, meaning they both have the same variable 'm'. When combining like terms, we simply add the coefficients (the numerical parts) and keep the variable unchanged. Therefore, 50m + 18m simplifies to 68m, which is in its simplest form.