Answer:
B. None of these plants is yet producing actual widgets.
Explanation:
As we can see in the graph, the number of days is on the x axis, and the number of widgets at y axis.
At 10 days, no line is above the '0' means no one is producing widgets at 10 days point.
Since the y axis represents number of widgets produced, this means none of the plants have produced more than 0 widgets yet.
So, option B is the answer.