When the earth is closest to the sun, it is at:
a. perihelion
c. aphelion
b. proxihelion
d. equinox

a). Perihelion . . . the point in Earth's orbit that's closest to the Sun.
                            We pass it every year early in January. 

b). Aphelion . . . the point in Earth's orbit that's farthest from the Sun.
                          We pass it every year early in July. 

c). Proxihelion . . . a made-up, meaningless word

d). Equinox . . . the points on the map of the stars where the Sun
                         appears to be on March 21 and September 21.