Within the exponential phase of growth , if the initial surface area and the growth rate of a leaf are `10 mm^(2)` and `0.015 mm^(2)`/hour respectively , the area of the leaf after 4 days would range from :
A. 10 to 12 `mm^(2)`
B. 20 to 24 `mm^(2)`
C. 30 to 36 `mm^(2)`
D. 40 to 48 `mm^(2)`
