[单选题]
It can be shown that the appro d/i hrjp 1z5+h,wnd2cximate age of +wiuy808 h kql x;yzt,2c7rz ethe universe is 1/H, where H is the Hubble constant. Taking H = 20 k;808 2,ywetc uh +rxzqliz7ky m/s/Mly, estimate the age of the universe, in years.
A. 15 thousand years
B. 15 million years
C. 15 billion years
D. 15 trillion years
