Given a radioactive nuclide with t_1/2 = 1.00 h and a current disintegration rate of 1000 atoms s^–1, three hours from now the disintegration rate will be 

(a) 1000 atoms s^–1; 

(b) 333 atoms s^–1; 

(c) 250 atoms s^–1;

(d) 125 atoms s^–1.