The result of a randomized controlled trial

The result of a randomized controlled trial was reported as follows:

“Compared to the control diet, the mean change in blood pressure for the treatment diet was -6.0 mmHg, P (comparing treatment vs control) = 0.01.  What does this mean?

A. Compared to the control diet, the treatment group resulted in a statistically significant decrease in blood pressure

B. Compared to the control diet, the treatment group resulted in a decrease in blood pressure, but the results were not statistically significant.

C. Compared to the control diet, the treatment group resulted in a increase in blood pressure, but the results were not statistically significant.

D. Compared to the control diet, the treatment group resulted in a statistically significant increase in blood pressure