Impossible to erase WD in disk utility

Hi WD,
I just bought an external hard drive WD Elements 1 To.

I work with El Capitan.
In disk utility, on the left, menu “external”, I see the line “WD elements 25A2 media” but not the second line below with the sign to click for erase.
So, impossible to go forward and to format on Mac.
Do you have a solution, please?

Problem solved in selecting the first and only line of WD in the menu.
Then, the second line line appears with the erase sign, and click on erase again, etc…
Have a good day!