Which of the following best describes when an infinite series ∑an is said to be "conditionally convergent"?
a) Both the series ∑an and ∑∣an∣ converge.
b) The series ∑an diverges, but the series ∑∣an∣ converges.
c) The series ∑an converges, but the series ∑∣an∣ diverges.
d) The sequence of partial sums of ∑an oscillates without approaching a finite limit.