Hi Arcee,   Solution B will work for you. In Stereophile test JA measured the ouput voltage of both XLR and RCA outputs and found that the XLR output voltage is exactly the double of the RCA's. Since you will use only the positive phase of the balanced output with the XLR-RCA adapter you...

Roksan M2 power amp has inputs and outputs on both RCA and XLR connectors. Did you plug the interconnect cables in the input connectors of the amp? There's a switch between the XLRs and RCAs to select which type of inputs you want to use. Check if the right one is selected.