While a Patient Receiving Iodine-131 (¹³¹I)therapy Is Hospitalized,a Large,_________,rolling Lead

While a patient receiving Iodine-131 (¹³¹I) therapy is hospitalized,a large,_________,rolling lead shield can be positioned between the patient and any attending personnel for protection.

A) up to 25-mm or 1-inch-thick
B) up to 50-mm or 2-inch-thick
C) up to 75-mm or 3-inch-thick
D) up to 150-mm or 6-inch-thick