How should cumulative preferred dividends in arrears be shown in a corporation's balance sheet?

a) Note disclosure <------------------------------------- answer

b) increase in stockholder's equity

c) increase in current liabilities

d) increase in current liabilities for the amount expected to be declared within the year or operating cycle, and increase in long term liabilities for the balance.

I know the answer is choice a but can someone explain to me why? I'm confused on the definition of note disclosure. Thanks in advance!