The amount of bacteria in a Petri dish increases at a rate proportional to the amount present. At time t=0, the amount of bacteria in the dish is 10 grams. At time t=2, the amount of the bacteria in the dish is 30 grams. What is the amount of bacteria in the dish at time t=6?
A. 70 grams
B. 190 grams
C. 270 grams
D. 9270 grams