What Is the Lateral Pressure (In Kips Per Square Foot

What is the lateral pressure (in kips per square foot (ksf) ) at the bottom of an 8-foot tall, 18-inch thick poured concrete retaining wall in an active pressure condition, given the backfill placed behind the wall is sandy gravel with a dry unit weight of 122 pounds per cubic foot (pcf) , and an internal friction of 28 degrees? Assume the wall does not retain water and the Rankin active earth pressure coefficient Ka = 0.33.

A) 0.32 ksf
B) 3.2 ksf
C) 322 ksf
D) Not enough information provided