Step 1: Define a floor price.
A price floor is a legally imposed minimum price below which market transactions cannot occur. It is set above equilibrium to protect producers.
Step 2: Match options.
- MSP (Minimum Support Price) is a classic policy example of a floor price used to protect farmers’ incomes.
- (B) “Price printed” is simply the listed/marked price, not a government floor.
- (C) “Price taken by seller” and (D) “Price asked by buyer” are bargaining quotes, not statutory minima.
Final Answer:
\[
\boxed{\text{Minimum Support Price (MSP) is a price floor.}}
\]