Which is the correct formula for calculating expected activity cost for three-point estimating?

Which is the correct formula for calculating expected activity cost for three-point estimating?

A.Ce = (C0 + 6Cm + Cp)/4

B.Ce = (6C0 + Cm + Cp)/4

C.Ce = (C0 + 4Cm + C

p)/6

D.Ce = (C0 + C-ž, + 4Cp) / 6