A nurse is preparing to administer packed RBCs to a client who has a low hemoglobin level. Which of the following actions should the nurse take prior to the start of the infusion?

A. Check that the client has a small gauge IV catheter in place:

While it is important to have an appropriate-sized IV catheter for blood transfusions, checking the compatibility of the blood product with the client's blood type is the primary concern before initiating the transfusion. The IV catheter size becomes relevant after confirming compatibility.

B. Check the blood product's compatibility with the client's blood type:

This is the first and most crucial step before administering any blood product. Ensuring compatibility between the packed red blood cells (PRBCs) and the client's blood type is vital to prevent a transfusion reaction. The nurse should carefully check the blood product against the client's 

C. Prime the client's primary IV tubing with lactated Ringer's:

Priming the tubing with lactated Ringer's is not the first step. The initial focus should be on verifying the compatibility of the blood product with the client's blood type. After ensuring compatibility, the nurse can then prime the tubing with the appropriate blood product.

D. Confirm the identity of the client with the blood bank technician:

Confirming the identity of the client with the blood bank technician is important, but it is not the first step before the start of the infusion. The immediate priority is to check the compatibility of the blood product with the client's blood type. Confirming the client's identity becomes crucial during the administration process.