Answer: The correct answer is Option B.
Step-by-step explanation:
An acid is defined as the substance which has more number of protons in the solution.
A compound is defined as the substance which can be chemically broken down into simpler substances. It is considered as a pure substance.
An element is defined as a substance which cannot be broken down into simpler substances by any chemical means. It is considered as a pure substance.
A solution is defined as a mixture of solute and solvent in which solute particles are homogeneously distributed among the solvent particles.
Letter B corresponds to the compound. Hence, the correct answer is option B.