SelectGraphs is an option for OneLoopSum
indicating that only a slected set of graphs of the list provided to
OneLoopSum is to be calculated. Possible settings are:
SelectGraphs -> {i, j, ...} or
SelectGraphs -> {a, {b, c}, ...} which indicates the
graphs to be taken from the list provided to OneLoopSum. In
the second setting the list {b, c} indicates that all
amplitudes from b to c should be taken.