Water boils at 100 Celsius at sea level ????? 

The answer is A true.

It is true that water boils at 100 degrees Celsius under standard atmospheric pressure. This temperature is defined as the normal boiling point of water.

The correct answer is A) True. Water boils at 100° Celsius (or 212° Fahrenheit) at standard atmospheric pressure, which is most often measured at sea level.

True, it normal.

Yes water boils at 100 degrees Celsius at a normal level. At sea level. It will boil at much higher above sea level. This is because, the higher you go, the cooler it becomes.