The correct answer is B) accumulation of sediment within the cells due to excessive overcharging and discharging. The accumulation of sediment within the lead-acid battery cells can cause the plates to partially short-out, leading to the battery's inability to hold a charge. Excessive overcharging and discharging can create this sediment buildup, as it causes the active material on the battery plates to break down and fall to the bottom of the cell, creating a conductive path between the positive and negative plates. The other options are incorrect because: A) Dirty or acid-wet tops and sides of batteries can cause corrosion, but do not directly lead to the plates shorting out. C) Sulfation of the plates is caused by consistent undercharging or leaving the battery in a discharged state, which is different from the sediment buildup issue. D) Lime accumulation on the terminal posts is a separate issue that does not cause the plates to short-out.