A7. Lake Baikal in Siberia is the deepest lake in the world. Its surface is at an elevation of 455 m above sea level, and its deepest point is 1165 m below sea level. What is the maximum depth of Lake Baikal?
(A) $-710 \mathrm{~m}$
(B) $710 \mathrm{~m}$
(C) $1165 \mathrm{~m}$
(D) $1620 \mathrm{~m}$
(E) None of the above.
A7. The greatest depth of Lake Baikal is $455+1165=1620 \mathrm{~m}$.