Which of the following statements is true?

a-During the 1960s and 1970s, regulatory constraints meant that banks could not in general satisfy the demand for consumer credit.

b-During the 1960s and 1970s, the credit union expansion ensured the availability of relatively low cost unsecured and secured personal loans.

c-During the 1960s and 1970s, the growth of building societies ensured an increasing supply of funds for housing loans at reasonable rates.

d-All of the listed options are correct.