A: float v1 = 1.0;
Invalid 1.0 is Double and it will need a cast to float because it is narrowing conversion
B: char v2 = "a";
"a" is a
String not a char like 'a'
C: byte v3 = -128;
this compiles because -128 is a constant expresion whith a value that is in the range for a byte (-128 , 127) Please read the JLS 5.2 because it is sure to be tested in the exam.
D: boolean v4 = null;
error null can be only asigned to reference variables, not to primitives
E: Float v5 = new Float(1.0);
ok, the constructor for Float can accept a float or a double