What is the domain of D(t) as it applies in this situation?

Answer:
t could be all real numbers.
Step-by-step explanation:
The function D(t) is given by:
[tex]D(t)=-1.5t+12[/tex]
The domain is all the posible x-values for which the function is defined.
In our case, t could be all real numbers.
The answer is the first option.
I hope it helps you!