The expression \( A(d) = 450(0.88)^x \) models the amount of radioactive material remaining after a certain number of days, \( x \). When we evaluate \( A(14) \), we are finding the amount of material left after 14 days.
To find \( A(14) \):
\[ A(14) = 450(0.88)^{14} \]
The interpretation of the statement \( A(14) = 75 \) is that after 14 days, there are 75 grams of the radioactive material left.
Therefore, the correct interpretation is:
B) in 14 days there is 75 g of radioactive material left.