What do astronomers mean by the term "hot Jupiters"?
a. planets with masses and composition similar to what we would expect if Jupiter were hotter
b. massive planets that orbit stars that are more massive and hotter than our Sun
c. planets with masses similar to Jupiter, but compositions that are similar to Mercury
d. planets with masses similar to Jupiter, but that orbit very close to their central star
e. planets with masses and orbits similar to Jupiter but for which infrared observations indicate they are surprisingly hot in temperature