Final answer:
The term 32h represents the charge for each hour of work, while the term 45 represents a fixed rate charge. The firm charges a fixed rate of $32 in addition to a charge of $45 for each hour they work.
Step-by-step explanation:
The expression 32h + 45 represents the total fee charged by a plumbing firm. The term 32h represents the charge for each hour of work, while the term 45 represents a fixed rate charge.
So, the correct statement is A.
The firm charges a fixed rate of $32 in addition to a charge of $45 for each hour they work.