B0[pp, ma^2, mb^2] is the Passarino - Veltman two-point integral B0. All arguments are scalars and have dimension mass^2. If the option BReduce is set to True certain B0's are reduced to A0's. Setting the option B0Unique to True simplifies B0[a,0,a] and B0[0,0,a].
The FeynCalc Book | Apart3 | B00 |