bookmark_borderYEAH, English ...!
Which one is it?

The gate build has easi­ly been
the most ner­ve _racking and expen­si­ve fea­ture of this project
..
the most ner­ve _recking and expen­si­ve fea­ture of this project
..
the most ner­ve wrecking and expen­si­ve fea­ture of this project
..
the most ner­ve wracking and expen­si­ve fea­ture of this project