以下不符合C语言语法的实型常量是（  ）。

A、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px; TEXT-DECORATION: none">1.2E0.5</span>

B、<span style="FONT-SIZE: 14px; TEXT-DECORATION: none">3.14.159E&nbsp; </span>

C、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">5E-3&nbsp;&nbsp;&nbsp; </span>

D、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px; TEXT-DECORATION: none">E15</span>