Correct increasing order for the wavelengths of absorption in the visible region for the complexes of $\require{mhchem}\ce{Co3+}$ is
(a) $\ce{[Co(H2O)6]^3+, [Co(en)3]^3+, [Co(NH3)6]^3+}$
(b) $\ce{[Co(H2O)6]^3+, [Co(NH3)6]^3+, [Co(en)3]^3+}$
(c) $\ce{[Co(NH3)6]^3+, [Co(en)3]^3+, [Co(H2O)6]^3+}$
(d) $\ce{[Co(en)3]^3+, [Co(NH3)6]^3+, [Co(H2O)6]^3+}$
(a) $\ce{[Co(H2O)6]^3+, [Co(en)3]^3+, [Co(NH3)6]^3+}$
(b) $\ce{[Co(H2O)6]^3+, [Co(NH3)6]^3+, [Co(en)3]^3+}$
(c) $\ce{[Co(NH3)6]^3+, [Co(en)3]^3+, [Co(H2O)6]^3+}$
(d) $\ce{[Co(en)3]^3+, [Co(NH3)6]^3+, [Co(H2O)6]^3+}$