How does the appearance of an array formula differ from that of a standard formula?

In a worksheet cell, array formulas have a small blue triangle in the cell’s upper-right corner.
A heavy border appears around the range that is occupied by the array formula.
In the formula bar, an array formula appears surrounded by curly brackets.
When a cell that contains an array formula is selected, range finders appear on the worksheet around the formula’s precedent cells.

The correct answer is: