Which of the following statements are correct? (A) The $\mathrm{M}^{3+} / \mathrm{M}^{2+}$ reduction potential for iron is greater than manganese (B) The higher oxidation states of first row d-block elements get stabilized by oxide ion. (C) Aqueous solution of $\mathrm{Cr}^{2+}$ can liberate hydrogen from dilute acid. (D) Magnetic moment of $\mathrm{V}^{2+}$ is observed between 4.4-5.2 BM Choose the correct answer from the options given below: