The correct answer is (b). Government securities are also known as gilt-edged securities. They are considered to be the safest type of investment because they are backed by the full faith and credit of the government. This means that the government is legally obligated to repay the principal and interest on the securities, even if it has to raise taxes or cut spending to do so.
Shares of public limited companies are not considered to be gilt-edged securities because they are not backed by the full faith and credit of the government. If a public limited company goes bankrupt, its shareholders may not get all of their money back.
Shares of private limited companies are even riskier than shares of public limited companies because they are not traded on a public stock exchange. This means that it is more difficult to sell them if you need to cash out.
Stocks of mutual funds are a type of investment that pools money from many different investors and invests it in a variety of assets, such as stocks, bonds, and other securities. Mutual funds are not considered to be gilt-edged securities because the value of their shares can go up or down, depending on the performance of the underlying assets.