Satellites in low-Earth orbits are more likely to crash to Earth when the sunspot cycle is near solar maximum because ________.
a. it is too dangerous to send the Space Shuttle to service satellites during solar maximum b. Earth's upper atmosphere tends to expand during solar maximum, exerting drag on satellites in low orbits
c. of increased magnetic interference
d. they are more likely to have their electronics "fried" by a solar flare during solar maximum
