To select an entire word in a document by using a touchscreen, ________ the word

In the code below

``` function Rectangle(x, y) { this.x = x; this.y = y; this.width = 40; this.height = 20; this.moveDown = function () { this.y += 5; }; } ``` rectangleA is ______. A. an object B. a constructor function

Briefly explain the difference between system testing and user acceptance testing (UAT).

What will be an ideal response?