Which of the following is correct for young's modulus of elasticity\[(\gamma )?\][where \[r=\]radius of cross section of wire, \[l=\]length of wire]

• A. \[\gamma \propto {{r}^{2}}\]
• B. \[\gamma \propto {{l}^{3}}\]
• C. \[\gamma \propto l/{{r}^{2}}\]
• D. \[\gamma \propto {{l}^{2}}\]