The district may provide for the funding or refunding of outstanding general obligation indebtedness pursuant to this article, if any of the following conditions exist:
(a)
The district has indebtedness evidenced by bonds, notes, or other evidences of indebtedness, which according to their terms are subject to call or payment before maturity.
(b)
The district has filed a petition under any bankruptcy law of the United States and refunding of its indebtedness is authorized in the bankruptcy proceedings.
(c)
The holder or holders of outstanding indebtedness has consented to exchange such outstanding bonds for refunding bonds bearing a lower rate of interest than such outstanding bonds.