[单选题]
The average life of a p:n 7:cxe0hlxf7ioc ;n animc if o9ju d+gr-op; *6ap;fo9nal is 70 years. Assume one numerical figure, write this f rn*dpi+-p9 o6oog;;j a9c fuin power of ten in seconds.
A. $3 \times 10^{7} \; s$
B. $2 \times 10^{7} \; s$
C. $2 \times 10^{9} \; s$
D. $3 \times 10^{9} \; s$
