Bernard and Adriana grew sunflowers in their backyard. Bernard's sunflower grew 4.23 centimeters in one week and 8.91 centimeters the second week. Adriana's sunflower grew 15.12 centimeters in two weeks. Over two weeks, how much more did Adriana's sunflower grow than Bernard's? 1.98 cm 4.68 cm 6.21 cm 10.89 cm