Hello,<br/><br/>1.No other metal is as costly as gold. ( Change the degree of the adjective)<br/><br/>A. Gold is costlier than any other metal.<br/><br/> OR<br/><br/> No other metal is costlier than gold.<br/><br/>B. Gold is the costliest metal.<br/><br/> OR<br/><br/> Gold is the costliest of all metal.<br/><br/>Are both alternatives correct?<br/><br/>Thanks.