The number of grams of a radioactive isotope present after t years is 1,500(1/2)^t. What does 1,500 represent if
t>0
A. The original number of grams of the radioactive isotope present
B. The number of grams of the radioactive isotope present after 1/2 year
C. The number of grams of the radioactive isotope present after 2 years
D. The final number of grams of the radioactive isotope present