Agent service

Mr.A who is a c&f agent paid transport freight on behalf of Mr.B .

who is liable to pay RCM in this case.
Mr.A or Mr.B

My conclusion is Mr.A is actual paid freight charges to transporter hence ,
Mr. A, is liable to pay RCM on freight.

why - As per Notification No
13/ 2017 , Dt
28/06/2017 , central Tax Rate
In this notification at the bottom explanation given as Under -

Persons who pays or is liable to pay freight for the transportation of goods by road in goods carriage, located in taxable territory shall be treated as the person who receives the service for the purpose of this notification.

So here first instance occured payment by Mr. A ( c&f) agent .Hence Mr.A is liable to pay RCM.

This conclusion is right or else. please guide