A transfer to C a debt due to him by B, A being then indebted to B. C sues B for the debt due to B to A. Is B entitled to set off the debt due by A-

According to the Transfer of Property Act, when a debt due from 'A' to 'B' is transferred to 'C' and 'A' is also indebted to 'B' at the same time, 'B' is entitled to set off the debt due from 'A' against the debt due to 'C'. This right of set-off applies even if 'C' was unaware of the debt owed by 'A' to 'B' at the time of the transfer.

The rationale behind this is to prevent unjust enrichment. If 'A' owes 'B' and 'C' owes 'A', it would be unfair to allow 'C' to recover the debt from 'B' without adjusting the amount 'A' owes 'B'. Therefore, 'B' is entitled to set off the debt owed by 'A' against the debt due to 'C', even if 'C' was unaware of it at the time of the transfer.

Therefore, the correct option is Option A: Yes although 'C' was unaware of it at the date of such transfer, as it accurately reflects the legal principle regarding the entitlement to set off in this context.