The correct answer is: Both B and C.
Tax-free bonds issued for welfare by industrial agencies or pollution control agencies are classified as development bonds and pollution control bonds.
Development bonds are a type of municipal bond that is issued to finance public projects that are intended to promote economic development. These projects can include things like infrastructure improvements, job training programs, and business development initiatives.
Pollution control bonds are a type of municipal bond that is issued to finance the construction or improvement of pollution control facilities. These facilities can include things like wastewater treatment plants, air pollution control systems, and hazardous waste disposal sites.
Both development bonds and pollution control bonds are exempt from federal income tax. This means that investors who purchase these bonds do not have to pay federal income tax on the interest that they earn from the bonds.
In addition, both development bonds and pollution control bonds are often exempt from state and local income taxes. This makes them a very attractive investment for investors who are looking for a tax-advantaged way to invest their money.