Which from following is a correct increasing order of basic strength of compounds?

Step-by-step solution

The basic strength of amines in aqueous solution depends on three competing factors: inductive effects , solvation effects , and steric hindrance . Alkyl groups exert an electron-donating inductive effect (+I), increasing electron density on the nitrogen atom and enhancing basicity. Solvation stabilizes the conjugate acid through hydrogen bonding: NH ₄^+ forms 4 H-bonds, CH ₃ NH ₃^+ forms 3, ( CH ₃)₂ NH ₂^+ forms 2, and ( CH ₃)₃ NH ^+ forms only 1. Greater solvation yields stronger basicity. Steric hindrance from b