The correct answer is (A) Ca
Element Ca belongs to s-block of periodic table and rest i.e., Ge, As and Br are elements of p-blocks. Non-metals are located at the top right hand side of the periodic table while metals are on the left hand side. The metals become more non-metallic as we go left to right side of a period in a periodic table. Hence the order for metallic to non- metallic nature will be Ca>Ge>As>Br.