What is a disadvantage of government bonds?

a) they have a high intrest rate

b) They are difficult to find

c) They are relatively risk-free

d) all of the above

None of those answers are suitable to me.

Government bonds are generally regarded as low-risk and they typically have modest (low) interest rates for return on investment, and these are advantages really. So we can discount answer A, C, and D.

I guess you could say that bonds can be hard to find (Answer B) but this not really true. There is always a bond market to trade bonds on. It requires setting up a trading account or speaking to a broker so this can be more difficult than putting money in a bank account, but to be honest I don't think any of those answers are appropriate for the question.