At Phil's Hot Dog Stand, We Found the Following: 4

At Phil's Hot Dog Stand, we found the following: 4 laborers produced 66 hot dogs
5 laborers produced 76 hot dogs
6 laborers produced 84 hot dogs
7 laborers produced 88 hot dogs
What was the marginal physical product of the sixth laborer?

A) 10 hot dogs
B) 8 hot dogs
C) 6 hot dogs
D) 4 hot dogs