Schweser Prac Exam Vol 2, PM Paper 2, Qn 15.5

Hi, Kinda confused over this question. Answer states that “Both callable bonds and bonds with long durations trade at a premium due to their scarcity.” Shouldn’t callable bonds trade at a discount? I thought only putable bonds trade at a premium due to their scarcity? Thanks in advance!

it is premium against fair value not par

Co anh chi em nguoi Viet nao tren day khong?