Parathese two times five parathese times parathese three times fifteen parathese
The correct answer is b. The domain of the function is in terms of x, so we are looking at the x-axis. The line stretches from 3 to 7 on the x-axis, so we know that b is our answer.
16 people would be at the dinner because Jim and Sarah invited 7 friends and each friend brought 1 guest, so you do 7*2=14 and the 14 + Jim and Sarah=16 people.
The answer to your question is A but i dont see a D option so it might be wrong