Doug can paint a room in 5 hours. Dave can paint the same room in 7 hours. Doug and Dave paint the room together and take a one-hour break for lunch. Let t be the total time, in hours, required for them to complete the job working together, including lunch. Which of the following equations is satisfied by t ?

**Answer Choices**

A. \left(\dfrac{1}{5}+\dfrac{1}{7}\right)(t+1)=1

B. \left(\dfrac{1}{5}+\dfrac{1}{7}\right) t+1=1

C. \left(\dfrac{1}{5}+\dfrac{1}{7}\right) t=1

D. \left(\dfrac{1}{5}+\dfrac{1}{7}\right)(t-1)=1

E. (5+7) t=1