How Far Will Comet Halley Be from the Sun When

How far will Comet Halley be from the Sun when it reaches its farthest point from the Sun, or aphelion, if its sidereal period is 76 years? (Note: This calculation needs Kepler's law and a little care. Assume that the comet's perihelion distance from the Sun is negligible.)

A) about 18 au, between the orbits of Saturn and Uranus
B) about 1324 au, well beyond the orbit of Pluto
C) about 9 au, between the orbits of Jupiter and Saturn
D) about 36 au, between the orbits of Neptune and Pluto