non-refundable bonds

CFA Level I
#1

for non-refundable bonds, is it allowed to issue common/preferred stock and call the bond? I know nonrefundable bonds cannot be paid off by cheaper debt, but not sure if either of common/preferred equity is considered as debt for this purpose

#2

I don’t think that should be an issue

#3

I think as long as its not in the form of lower cost of debt than equity financing is fine.