Answer:
Option A.
Placing a semicolon at the end of the first line of an if statement.
Explanation:
Compilation error refers to a state when a compiler fails to compile a piece of computer source code, either due to errors in the code or more unusually, due to errors in the compiler itself.
When you get a compilation error, various things can be wrong: you may have made a lexical, parse, static or a type error.
* Option A, placing a semicolon at the end of the first line of an IF statement is not a compilation error so it is correct.
* Option B, omitting the left and ) for the condition of an IF statement is a syntax error under compilation error, so the option is incorrect.
* Option C, Neglecting to initialize a local variable in a method before it is used is also incorrect because local variables which are variables declared inside a body of a method must be initialized before they can be used, failure to do so will generate a compiler error.
* Option D, all are compilation errors is also incorrect because option A is not a compilation error.
Therefore, the answer to the question is option A.