Which line of code should you use?

You are testing the value of the following variable in JavaScript.

var height = "300";

A block of code must execute if the following conditions are true:

• The height variable is set to 300

• The height variable is of type string

You need to implement the code to run the test.

Which line of code should you use?
A . if (height = = 300)
B . if (height = = “300")
C . if (height ! "300")
D . if (height ! = 300)