Which of the following is a valid ESD safety precaution?

A. You should place ESD-sensitive circuits on top of metal work surfaces.
B. Keep ion generators away from circuit board or assembly containing ESD-sensitive circuits.

C. Do not wear polyester clothing while working on ESD sensitive components.

D. Always handle logic board by grasping the heat sinks.

Reference: http://www.peachpit.com/articles/article.aspx?p=759704