After you replace $x$ with $3$, you will get an expression like $7-4(3)$. Which operation should you perform first: the subtraction or the multiplication?

Once you multiply $4$ and $3$, you will have $7$ minus that product. Make sure you are doing $7$ minus the product, not the product minus $7$.

In one line, type h(x)=7-4x, and in the next line type h(3). Look at the numerical value that Desmos displays for h(3); that value is the answer to the question.

The function is defined as $h(x)=7-4x$. The question asks for the value of $h(x)$ when $x=3$, which means you need to find $h(3)$ by plugging $3$ in place of $x$ in the expression $7-4x$.

Replace $x$ with $3$ in $h(x)=7-4x$:

Now you have a numerical expression to simplify.

First multiply $4\cdot 3$ to get $12$, so the expression becomes:

Now subtract: $7-12=-5$. So $h(3)=-5$, which corresponds to answer choice C.