A Plane Flying Horizontally at an Altitude of 1 Km $125 \sqrt { 3 } \mathrm {~km} / \mathrm { h }$

A plane flying horizontally at an altitude of 1 km and a speed of 500 km/h passes directly over a radar station. Find the rate at which the distance from the plane to the station is increasing when it is 2 km away from the station.

A) $125 \sqrt { 3 } \mathrm {~km} / \mathrm { h }$

B) $175 \sqrt { 3 } \mathrm {~km} / \mathrm { h }$
C) $250 \sqrt { 3 } \mathrm {~km} / \mathrm { h }$
D) $275 \sqrt { 3 } \mathrm {~km} / \mathrm { h }$
E) $125 \sqrt { 2 } \mathrm {~km} / \mathrm { h }$
F) $175 \sqrt { 2 } \mathrm {~km} / \mathrm { h }$

G) $250 \sqrt { 2 } \mathrm {~km} / \mathrm { h }$

H) $275 \sqrt { 2 } \mathrm {~km} / \mathrm { h }$